Sacrificial agents for fly ash concrete

ABSTRACT

A method of producing cementitious mixtures containing fly ash as one of the cementitious components, under air entrainment conditions. The method involves forming a mixture comprising water, cement, fly ash, optionally other cementitious materials, aggregate, conventional chemical admixtures, and an air entrainment agent and agitating the mixture to entrain air therein. Additionally, at least one sacrificial agent is also included in the mixture. The sacrificial agent is a material or mixture of materials that is not required to act as an air entrainment agent but interacts preferentially with components of the fly ash that otherwise neutralize, repress or depress the activity of the air entrainment agent. The invention includes cementitious mixtures and hardened concretes resulting from the method and fly ash treated with sacrificial agent, or air entrainment agent/sacrificial agent combinations, and processes for selecting suitable sacrificial agents.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 10/762,762, filed Jan. 22, 2004, now U.S Pat. No, 7,485,184 which isrelated to commonly owned provisional application Ser. No. 60/442,048,filed Jan. 24, 2003, and claims the benefit of the earlier filing dateof this application under 35 U.S.C. §119(e). The disclosure ofprovisional application Ser. No. 60/442,048 is incorporated hereby byreference in its entirety.

BACKGROUND OF THE INVENTION

I. Field of the Invention

This invention relates to the use of sacrificial agents in fly ashconcrete and similar cementitious mixtures, and to the resultingmixtures and compositions. More particularly, the invention relates tosacrificial agents that reduce or eliminate detrimental effects of flyash on the air entrainment properties of fresh concrete and similarmixtures.

II. Background Art

The partial replacement of portland cement by fly ash is growingrapidly, driven simultaneously by more demanding performancespecifications on the properties of concrete and by increasingenvironmental pressures to reduce portland cement consumption. Fly ashcan impart many beneficial properties to concrete such as improvedrheology, reduced permeability and increased later-age strength;however, it also may have a negative influence on bleed characteristics,setting time and early strength development. Many of these issues can bemanaged by adjusting mixture proportions and materials, and by alteringconcrete placement and finishing practices. However, other challengingproblems encountered when using certain fly ash are not always easilyresolved. The most important difficulties experienced when using fly ashare most often related to air entrainment in concrete.

Air entrained concrete has been utilized in the United States since the1930's. Air is purposely entrained in concrete, mortars and grouts as aprotective measure against expansive forces that can develop in thecement paste associated with an increase in volume resulting from waterfreezing and converting to ice. Adequately distributed microscopic airvoids provide a means for relieving internal pressures and ensuringconcrete durability and long term performance in freezing and thawingenvironments. Air volumes (volume fraction) sufficient to provideprotective air void systems are commonly specified by Building Codes andStandard Design Practices for concrete which may be exposed to freezingand thawing environments. Entrained air is to be distinguished fromentrapped air (air that may develop in concrete systems as a result ofmixing or the additions of certain chemicals). Entrained air provides anair void system capable of protecting against freeze/thaw cycles, whileentrapped air provide no protection against such phenomena.

Air is also often purposely entrained in concrete and other cementitioussystems because of the properties it can impart to the fresh mixtures.These can include: improved fluidity, cohesiveness, improved workabilityand reduce bleeding.

The air void systems are generated in concrete, mortar, or pastemixtures by introducing air entrainment admixtures (referred to as airentrainment agents or air-entraining agents) which are a class ofspecialty surfactants. When using fly ash, the difficulties in producingair-entrained concrete are related to the disruptive influence that somefly ashes have on the generation of sufficient air volumes and adequateair void systems. The primary influencing factor is the occurrence ofresidual carbon, or carbonaceous materials (hereafter designated as flyash-carbon), which can be detected as a discrete phase in the fly ash,or can be intimately bound to the fly ash particles. Detrimental effectson air entrainment by other fly ash components may also occur, andindeed air entrainment problems are sometimes encountered with fly ashcontaining very low amounts of residual carbon.

Fly ash-carbon, a residue of incomplete coal or other hydrocarboncombustion, is in many ways similar to an ‘activated carbon’; as typicalof the latter, fly ash-carbon can adsorb organic molecules in aqueousenvironments. In cement paste containing organic chemical admixtures,the fly ash-carbon can thus adsorb part of the admixture, interferingwith the function and performance of the admixture. The consequences ofthis adsorption process are found to be particularly troublesome withair entrainment admixtures (air entrainment agents) which are commonlyused in only very low dosages. In the presence of significant carboncontents (e.g. >2 wt %), or in the presence of low contents of highlyreactive carbon or other detrimental fly ash components, the airentrainment agents may be adsorbed, interfering with the air voidformation and stability; this leads to tremendous complications inobtaining and maintaining specified concrete air contents.

To minimize concrete air entrainment problems, ASTM guidelines havelimited the fly ash carbon content to less than 6 wt %; otherinstitutions such as AASHTO and State departments of transportation havemore stringent limitations. Industry experience indicates that, in thecase of highly active carbon (for example, high specific surface area),major interferences and problems can still be encountered, even withcarbon contents lower than 1 wt %.

Furthermore, recent studies indicate that, while fly ash carbon content,as measured by loss on ignition (LOI) values, provides a primaryindicator of fly ash behaviour with respect to air entrainment, it doesnot reliably predict the impact that a fly ash will have on airentrainment in concrete. Therefore, there currently exist no means,suitable for field quality control, capable of reliably predicting theinfluence that a particular fly ash sample will have on air entrainment,relative to another fly ash sample with differing LOI's, sources, orchemistries. In practice, the inability to predict fly ash behaviourtranslates into erratic concrete air contents, which is currently themost important problem in fly ash-containing concrete.

Variations in fly ash performance are important, not only because oftheir potential impact on air entrainment and resistance to freeze thawconditions, but also because of their effects related to concretestrength. Just as concrete is designed according to Building Standardsfor a particular environment, specifications are also provided forphysical performance requirements; a common performance requirementbeing compressive strength. An increase in entrained air content canresult in a reduction in compressive strength of 3-6% for eachadditional percentage of entrained air. Obviously, variations in flyash-carbon, which would lead to erratic variations in air contents, canhave serious negative consequences on the concrete strength.

The fly ash-carbon air entrainment problem is an on-going issue that hasbeen of concern since fly ash was first used nearly 75 years ago. Overthe past ten years, these issues have been further exacerbated byregulations on environmental emissions which impose combustionconditions yielding fly ash with higher carbon contents. This situationthreatens to make an increasingly larger portion of the available flyash materials unsuitable for use in concrete. Considering the economicimpact of such a trend, it is imperative to develop practical correctiveschemes which will allow the use, with minimal inconvenience, of fly ashwith high carbon contents (e.g., up to 10 wt %) in air-entrainedconcrete.

Air entrainment in fly ash-concrete may become yet more complicated bypending regulations that will require utilities to reduce current Hgemissions by 70-90%. One of the demonstrated technologies for achievingthe Hg reduction is the injection of activated carbon into the flue gasstream after combustion so that volatile Hg is condensed on the highsurface area carbon particles and discarded with the fly ash. Currentpractices are designed such that the added activated carbon is generallyless than 1% by mass of the fly ash, but preliminary testing indicatesthis is disastrous when using the modified fly ash in air-entrainedconcrete.

The origin of air entrainment problems in fly ash concrete, andpotential approaches to their solution, have been the subject ofnumerous investigations. Most of these investigations focused on the‘physical’ elimination of the carbon by either combustion processes,froth floatation, or electrostatic separation. To date, the proposed flyash treatment approaches have found limited application due to theirinherent limitations (e.g., separation techniques have limitedefficiency in low carbon fly ash; secondary combustion processes aremost suitable for very high carbon contents), or clue to theirassociated costs.

“Chemical” approaches have also been proposed to alleviatecarbon-related problems in concrete air entrainment, for example throughthe development of alternative specialty surfactants for air entrainmentagents such as polyoxyethylene-sorbitan oleate as an air entrainmentagents (U.S. Pat. No. 4,453,978). Various other chemical additives orfly ash chemical treatments have been proposed, namely:

-   -   the addition of inorganic additives such as calcium oxide or        magnesium oxide (U.S. Pat. No. 4,257,815); this invention        prescribes the use of inorganic additives which may influence        other properties of fresh mortars or concrete, for example, rate        of slump loss and setting time;    -   the addition of C8 fatty acid salts (U.S. Pat. No. 5,110,362);        the octanoate salt is itself a surfactant, and it is said to        “stabilize the entrained air and lower the rate of air loss”        (Claim 1 of U.S. Pat. No. 5,110,362);    -   the use of a mixture of high-polymer protein, polyvinyl alcohol        and soap gel (U.S. Pat. No. 5,654,352); this discloses the use        of protein and polyvinyl alcohol, and optionally a colloid (for        example, bentonite) to formulate air entrainment admixtures;    -   treatment with ozone (U.S. Pat. No. 6,136,089); the ozone        oxidizes fly ash-carbon, reducing its absorption capacity for        surfactants and thus making the fly ash more suitable for use in        air entrained systems.

While each of the proposed solution may have potential merit, none hasfound significant acceptance in the industry, either because of theircomplexity and cost, or because of their limited performance in actualuse. For example, a clear limitation to the addition of a secondsurfactant (e.g., C8 fatty acid salt), to compensate for the adsorptionof the air entrainment agents surfactant, simply shifts the problem tocontrolling air content with a combination of surfactants instead of asingle one. The problem of under- or over-dosage of a surfactant mixtureis then the same as the problem discussed above with conventional airentrainment agents.

Hence, no practical solution currently exists which could efficientlyrelieve air entrainment problems for a wide variety of fly ashmaterials, in ready mix facilities or in the field.

SUMMARY OF THE INVENTION

An object of the present invention is to facilitate the formation ofcementitious mixtures containing fly ash, and solid products derivedtherefrom.

Another object of the invention is to facilitate air entrainment intosuch mixtures in a reliable and predictable fashion.

According to one aspect of the present invention, there is provided amethod of producing an air-entraining cementitious mixture containingfly ash, comprising the steps of: forming a mixture comprising water,cement, fly ash, (and optionally other cementitious components, sand,aggregate, etc.) and an air entrainment agent (and optionally otherconcrete chemical admixtures); and entraining air in the mixture;wherein an amount of at least one sacrificial agent is also included inthe mixture, the at least one sacrificial agent being a material that,when present in the mixture in the amount, need not itself act as an airentrainment agent and interacts preferentially with components of thefly ash that otherwise neutralize activity of the air entrainment agent,thereby permitting the air entrainment agent to function to entrain airin the mixture.

The amount of the sacrificial agent used in the cementitious mixturepreferably exceeds the amount necessary to interact with all of thecomponents of the fly ash. Thus, if the fly ash varies in content of thedetrimental components from a minimum content to a maximum contentaccording to the source or batch of the fly ash, the amount of thesacrificial agent preferably exceeds the amount necessary to interactwith all of the detrimental components of the fly ash when present attheir maximum content.

The sacrificial agent is preferably an aromatic organic compound bearingone or more sulfonate, carboxylate or amino group, and combinations ofsuch groups, a glycol or glycol derivate having molecular weights ofabout 2000 Da or less, and any combination thereof. More preferably, thesacrificial agent is benzylamine, sodium 1-naphthoate, sodium2-naphthalene sulfonate, sodium di-isopropyl naphthalene sulfonate,sodium cumene sulfonate, sodium di-butyl naphthalene sulfonate, ethyleneglycol phenyl ether, ethylene glycol methyl ether, butoxyethanol,di-ethylene glycol butyl ether, di-propylene glycol methyl ether,polyethylene glycol and 1-phenyl 2-propylene glycol or a combinationthereof. A combination of ethylene glycol phenyl ether and sodiumdi-isopropyl naphthalene sulfonate is particularly preferred, whereinthe relative proportion of the ethylene glycol phenyl ether and thesodium di-isopropyl naphthalene sulfonate may vary in weight ratio from1:5 to 50:1, and preferably in the range of about 1:1 to 20:1.

Even more preferably, the sacrificial agent is a compound selected fromalcohols, diols, polyols, ethers, esters, carboxylic acids, carboxylicacid derivatives, aromatic sulfonates, amines, alcoholamines, amides,ammonium salts, and polyglycols, particularly those for which LogKow isin the range of −3 to +2 (more preferably −2 to +2), and/or the HLBvalue is in the range of 5 to +20.

The total dosage of these combined sacrificial agents may vary widely.While there is no theoretical limit to the dosage of sacrificial agents(some may be added to considerable excess without detrimental effect),the practical maximum dosage would be that at which some property of themixture, e.g. setting time, fluidity, bleeding, etc., would be affectedsignificantly. With some sacrificial agents, this could be as high as0.5% by weight of the cementitious material; if typically the fly ashconstitutes 25 wt % of the cementitious material, the correspondingmaximum dosage by wt of the fly ash would thus be 2.0%. From a costperspective, depending on the particular sacrificial agent and otherfactors, the practical upper limit may commonly be in the order of 0.2%by weight of the cementitious material.

Preferably, the dosages vary from 0.01% to 0.5% by weight ofcementitious materials (cement and fly ash) depending on the type andcomposition of the fly ash; more preferably the total dosage is in therange of 0.01% to 0.2%. In terms of the concentration of sacrificialagents relative to the fly ash, the total dosage is preferably from0.01% to 1% by weight (wt/wt), or more preferably 0.02% to 0.5% byweight, or 0.02% to 0.2% by weight. Concentration relative to fly ash isimportant when the sacrificial agent is added first to the fly ash. If,typically, the fly ash is added in an amount of 30:70 by weight relativeto the cement, a concentration range of 0.1% to 0.2% by weight fly ashwould then translate to a range of 0.03% to 0.06% by weight of thecementitious material.

The sacrificial agent may be added to the air entrainment agent prior tomixing the air entrainment agent with the fly ash, cement and water.Alternatively, the sacrificial agent may be added to the fly ash priorto mixing the fly ash with the cement, water and the air entrainmentagent. In the latter case, the sacrificial agent may be added to the flyash by spraying a liquid containing the sacrificial agent onto the flyash, or by blending a spray-dried solid sacrificial agent formulationwith the fly ash.

Alternatively, the sacrificial agent may be added after the fly ashcement, water and conventional air entrainment agent have been mixedtogether.

The invention also relates to an air-entraining cementitious mixtureproduced by the process as described above, and a hardened mass ofcementitious material produced by setting and hardening the airentrainment cementitious mixture.

According to another aspect of the invention, there is provided anair-entraining cementitious mixture containing air, water, cement, flyash, an air entrainment agent and an amount of sacrificial agent, thesacrificial agent being a material that, when present in the mixture inthe appropriate amount, does not itself act as an air entrainment agentto a substantial amount (i.e. less than 2% vol of air entrainment), butinteracts preferentially with components of the fly ash that neutralizethe activity of the air entrainment agent, thereby permitting the airentrainment agent to function to entrain air as if the components werenot present in the fly ash.

According to another aspect of the invention, there is provided anair-entraining (air-entrained) hardened cementitious mass containingair, water, cement, fly ash, an air entrainment agent and an amount ofat least one sacrificial agent, the sacrificial agent being a materialthat, when present in an amount in a mixture, which is a precursor ofthe hardened mass, does not itself act as an air entrainment agent butinteracts preferentially with components of the fly ash that neutralizethe activity of the air entrainment agent, thereby permitting the airentrainment agent to function to entrain air as if the components werenot present in the fly ash.

According to yet another aspect of the invention, there is provided amixture (composition) suitable for use as a component of fly ashconcrete or mortar, the mixture comprising fly ash and at least onesacrificial agent, the sacrificial agent being a material that does notitself act as an air entrainment agent when mixed with cement powder, anair entrainment agent and water, but interacts preferentially withcomponents of the fly ash that neutralize activity of the airentrainment agent, thereby permitting the air entrainment agent tofunction as if the components were not present in the fly ash.

According to yet another aspect of the invention, there is provided amixture suitable for use as a component of fly ash concrete or mortar,the mixture comprising an air entrainment agent and at least onesacrificial agent, the sacrificial agent being a material that does notitself act as an air entrainment agent when mixed with cement powder andwater but interacts preferentially with components of the fly ash thatneutralize activity of the air entrainment agent, thereby permitting theair entrainment agent to function as if the components were not presentin the fly ash.

The invention additionally relates to a mixture of sacrificial agentsfor use in the preparation of an air entrainment fly ash concrete, themixture comprising a combination of ethylene glycol phenyl ether with orwithout the addition of sodium di-isopropyl naphthalene sulfonate andother typical air entrainment admixture surfactants.

The invention also relates to methods of selecting suitable sacrificialagents from candidate compounds.

In one form of the present invention, compounds suitable as sacrificialagents may be compounds other than aromatic carboxylic acids or saltsthereof (specifically hydroxyl-substituted aromatic carboxylic acids andsalts, e.g. benzoic acid, phthalic acid, isophthalic acid, terephthalicacid and their salts, or salicylic acid, m-hydroxybenzoic acid,p-hydroxybenzoic acid, and their salts (e.g. lithium salicylate)). Insuch a form of the invention, these compounds are specifically excludedfrom the scope of claim.

In another form of the present invention, compounds suitable assacrificial agents may include aromatic carboxylic acids or saltsthereof (specifically hydroxyl-substituted aromatic carboxylic acids andsalts, e.g. benzoic acid, phthalic acid, isophthalic acid, terephthalicacid and their salts, or salicylic acid, m-hydroxybenzoic acid,p-hydroxybenzoic acid, and their salts (e.g. lithium salicylate)).

As noted above, the invention concerns the novel uses of selectedchemical additives, labelled “sacrificial agents” to eliminate ordrastically reduce air entrainment problems encountered in concretecontaining fly ash. Such additives, or combinations of such additives,may be added before (e.g. in the fly ash material), during, or after theconcrete mixing operation. The use of these materials has the followingadvantages, at least in preferred forms of the invention. They:

-   -   enable adequate levels (typically 5-8 vol %) of gas, normally        air, to be entrained in concrete or other cemetitious products,        with dosages of conventional air entrainment agents that are        more typical of those required when no fly ash, or fly ash with        low carbon content, is used;    -   confer predictable air entrainment behaviour onto fly        ash-concrete regardless of the variability in the fly ash        material, such as the source, carbon content, chemical        composition;    -   do not interfere with cement hydration and concrete set time;    -   do not alter other physical and durability properties of        concrete;    -   do not significantly alter their action in the presence of other        concrete chemical admixtures, for example, water reducers,        superplasticizers and set accelerators; and    -   do not cause detrimental effects when added in excessive        dosages, such as excessive air contents, extended set times, or        strength reduction.

The acceptability of ‘over dosage’ of these sacrificial agents is a keypreferred feature of the present invention, at least in its main forms,since large fluctuations in fly ash properties (carbon content,reactivity, etc.) can be accommodated by introducing a moderate excessof these sacrificial agents without causing other problems. Thisprovides operators with a substantial trouble-free range or ‘comfortzone’.

The cementitious mixtures of the present invention may containconventional ingredients such as sand and aggregate, as well as specificknown additives.

DEFINITIONS

The term “fly ash”, as defined by ASTM C 618 (Coal Fly Ash or CalcinedNatural Pozzolan For Use in Concrete) refers to a by product of coalcombustion. However, the present invention may employ similar combustionproducts which are fine ashes or flue dusts resulting from co-firingvarious fuels with coal, or resulting from the combustion of other fuelsthat produce an ash having pozzolanic qualities (the ability to form asolid when mixed with water and an activator such ash lime or alkalis)or hydraulic qualities (the ability to form a solid when mixed withwater and set). The ash itself has pozzolanic/hydraulic activity and canbe used as a cementitious material to replace a portion of portlandcement in the preparation of concrete, mortars, and the like. Ingeneral, the term fly ash as used herein includes:

-   -   1) Ash produced by co-firing fuels including industrial gases,        petroleum coke, petroleum products, municipal solid waste, paper        sludge, wood, sawdust, refuse derived fuels, switchgrass or        other biomass material, either alone or in combination with        coal.    -   2) Coal ash and/or alternative fuel ash plus inorganic process        additions such as soda ash or trona (native sodium        carbonate/bicarbonate used by utilities).    -   3) Coal ash and/or alternative fuel ash plus organic process        additives such as activated carbon, or other carbonaceous        materials, for mercury emission control.    -   4) Coal ash and/or alternative fuel ash plus combustion        additives such as borax.    -   5) Coal ash and/or alternative fuel gases plus flue gas or fly        ash conditioning agents such as ammonia, sulfur trioxide,        phosphoric acid, etc.

The term “fly ash concrete” means concrete containing fly ash andportland cement in any proportions, but optionally additionallycontaining other cementitious materials such as blast furnace slag,silica fume, or fillers such as limestone, etc. The proportions in whichfly ash is typically used in concrete is well known to persons skilledin the art and is often in the range of 20-40% by weight of cementitiousmaterials and may go up to 60 to 80% in so-called High Volume Fly Ashconcrete.

The term “surfactants” is also well understood in the art to meansurface active agents. These are compounds that have an affinity forboth fats (hydrophobic) and water (hydrophilic) and so act as foamingagents (although some surfactants are non-foaming, e.g. phosphates),dispersants, emulsifiers, and the like, e.g. soaps.

The term “air entrainment agent” (AEA) means a material that results ina satisfactory amount of air being entrained into a cementitous mixture,e.g. 5-9 vol % air, when added to a cementitious formulation. Generally,air entrainment agents are surfactants (i.e. they reduce the surfacetension when added to aqueous mixtures), and are often materialsconsidered to be soaps.

The mode of action of air entrainment agents, and the mechanism of airvoid formation in cementitious mixtures are only poorly understood.Because of their influence on the surface tension of the solution phase,the surfactant molecules are believed to facilitate the formation ofsmall air cavities or voids in the cementitious paste, by analogy toformation of air ‘bubbles’. It is also believed that the wall of thesevoids are further stabilized through various effects, such asincorporation into the interfacial paste/air layer of insoluble calciumsalts of the surfactants, or of colloidal particles (see References 1-3at the end of this description).

The performance of surfactants as concrete air entrainment admixturedepends on the composition of the surfactant: the type of hydrophilicgroup (cationic, anionic, zwitterionic, or non-ionic), the importance ofits hydrophobic residue (number of carbon groups, molecular weight), thechemical nature of this residue (aliphatic, aromatic) and the structureof the residue (linear, branched, cyclic), and on the balance betweenthe hydrophilic and lipophilic portions of the surfactant molecule(HLB). Cationic and non-ionic surfactants were reported to entrain moreair than anionic surfactants because the latter are often precipitatedas insoluble calcium salts in the paste solution; however, the stabilityof the air void has also been reported to be greater with anionicsurfactant than with cationic or non-ionic surfactants. Typical examplesof compounds used as surface active agents are sodium salts of naturallyoccurring fatty acid such as tall oil fatty acid, and sodium salts ofsynthetic n-alkylbenzene sulfonic acid. As noted in Reference 2 at theend of this description, common concrete air entrainment (orair-entraining) agents include those derived from the following anionicsurfactants: neutralized wood resins, fatty acids salts, alkyl-arylsulfonates, alkyl sulfates.

The term “sacrificial agent” (SA) means a material, or a mixture ofmaterials, that preferentially interacts with (and/or neutralizes thedetrimental effects of) components of fly ash that would otherwiseinteract with an air entrainment agent and reduce the effectiveness ofthe air entrainment agent to incorporate air (or other gas) into thecementitious mixture. The sacrificial agents, need not be ‘surfactants’nor ‘air entrainment agents’ and, in the amounts used in thecementitious mixture, must not themselves act to entrain more thannominally 2 vol % additional air (more desirably less than 1 vol %additional air) into a similar control mixture containing no fly ash.Preferably, the sacrificial agent, in the amounts employed in flyash-containing mixtures, is responsible for introducing substantially noair into a similar control mixture containing no fly ash. Thesacrificial agent should also preferably not reduce the ability of theair entrainment agent to incorporate air (i.e. they should preferablynot have a “defoaming” effect). Ideally, the sacrificial agent shouldpreferably neither promote nor inhibit the functioning of the airentrainment agent compared with its functioning in a similar mixturecontaining no fly ash.

The term “cementitious mixture” means a mixture such as concrete mix,mortar, paste, grout, etc., that is still in castable form and that,upon setting, develops into a hardened mass suitable for building andconstruction purposes. Likewise, the term “cement” means a product(other than fly ash) that is capable of acting as the principalhardenable ingredient in a cementitious mixture. The preferred cementis, of course, portland cement, but at least a portion may include blastfurnace slag, gypsum, etc.

The term “second protocol rating” means a rating awarded to a compoundaccording to the procedure set out later in this description under theheading “SECOND PROTOCOL TO IDENTIFY ADDITIONAL SACRIFICIAL AGENTS”.

The term “percent” or “%” as used herein in connection with a componentof a composition means percent by weight based on the cementitiouscomponents (cement powder and fly ash) of a cementitious mixture (unlessotherwise stated). When referring to air content, the term % meanspercent by volume or vol %.

ABBREVIATIONS Sacrificial Agents

Benzylamine BA Sodium isopropyl benzene sulfonate Cumene Sodium di-butylnaphthalene sulfonate DBNS Di-ethylene glycol butyl ether Di-EGBEDi-propylene glycol methyl ether Di-PGME Ethylene glycol methyl etherEGME Ethylene glycol phenyl ether EGPE 1-Naphthoic acid sodium salt NASodium Di-isopropopyl naphthalene sulfonate ND Sodium 2-Naphthalenesulfonate NS Polyethylene glycol (Molecular weight = 200) PEG 200Polyethylene glycol (Molecular weight = 1500) PEG 1500 1-Phenyl2-propylene glycol 1-Phe 2-Pro

Other

Fly Ash FA portland cement A PCA portland cement C PCC Sacrificial agentSA Commercial air entrainment agents e.g. Air 30 and Air 40 Airentrainment agents or admixtures AEA relative to cementitious materials(CM) wt % Amount of air entrained vol % Average of Air Entrained Aver(%) Relative Standard Deviation RSD (%) DDBS Sodium dodecylbenzenesulfonate HLB Hydrophilic Lipophilic Balance K_(ow) Ratio of solubilityin oil (octanol) and in water LogK_(ow) Logorithm of K_(ow) LOI Loss onignition

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chart based on the results shown in Table 13 below whichillustrates how the addition of the sacrificial agent EGPE changes theair entrainment in mortars with and without fly ash. Each group of 3bars shows air entrained with: first 0.005% Air 40 only; second 0.005%Air 40 plus 0.05% EGPE and third 0.005% Air 40 plus 0.1% EGPE. The barsidentified ‘PCA’ refer to results obtained in control mortars containing0.004% Air 40 and no fly ash.

FIG. 2 is a graph based in the results shown in Table 17 below. Thegraph shows the amount of air entrained in concrete containing no flyash, a conventional air entrainment agent (Air 40) and increasingamounts of a sacrificial agent according to the present invention(EGPE). Trace A shows the results for mixtures containing 0.006% Air 40and Trace B shows the results for mixtures containing 0.003% Air 40. Thehorizontal shaded bar illustrates the range of typical EGPE dosages.

FIG. 3 is a graph based on the results shown in Table 26 whichillustrate the influence of increasing dosages of sodium di-isopropylnaphthalene sulfonate (ND) on air entrainment in concrete containing 75%PCA cement and 25% B1 fly ash (4.7% LOI) and Air 40 at 0.008 wt %, andEGPE at 0.05% (curve A) or 0.035% (curve B). The upper line refers toconcrete containing Air 40 at 0.008 wt %, but no fly ash and nosacrificial agents. The lower line refers to concrete containing 25% B1fly ash (4.7% LOI), Air 40 at 0.008 wt % and no sacrificial agents.

FIG. 4 is a graph based on the results shown in Table 28 below whichillustrate the influence of increasing dosages of ethylene glycol phenylether (EGPE) on air entrainment in concrete containing 75% PCC cementand 25% H2 fly ash (3.6% LOI (curve A) and 4.9% LOI (curve B)), Air 40at 0.005 wt %, and sodium di-isopropyl naphthalene sulfonate at 0.0016wt %. The upper line refers to concrete containing Air 40 at 0.005 wt %,but no fly ash and no sacrificial agents.

FIG. 5 is a graph based on the results shown in Table 29 below whichillustrate the influence of increasing dosages of a 1:3 mixture ofND:EGPE on air entrainment in concrete containing 75% PCC cement and 25%B1 fly ash (2.1% LOI (curve A), 4.7% LOI (curve B) and 5.7% LOI (curveC)) and Air 40 at 0.012 wt %. The upper line refers to concretecontaining Air 40 at 0.012 wt %, but no fly ash and no sacrificialagents.

FIG. 6 is a graph based on the results shown in Table 30 below whichillustrate the influence of increasing dosages of a 1:3 mixture ofND:EGPE on air entrainment in concrete containing 75% PCC cement and 25%E1 fly ash (1.3% LOI (curve A) and 2.3% LOI (curve B)) and Air 40 at0.005 wt %. The upper line refers to concrete containing Air 40 at 0.005wt %, but no fly ash and no sacrificial agents.

FIG. 7 is a graph based on the results shown in Table 31 below whichillustrate the influence of increasing dosages of a 1:3 mixture ofND:EGPE on air entrainment in concrete containing 75% PCC cement and 25%C1 fly ash (0.62% LOI) and Air 40 at 0.003 wt %. The upper line refersto concrete containing Air 40 at 0.003 wt %, but no fly ash and nosacrificial agents.

FIGS. 4 to 7 show that, in all cases tested, the air entrained in flyash concrete is severely reduced when the fly ash has significant losson ignition (LOI) values. However, the level of reduction is not alwaysrelated to the LOI values of the fly ash. Using the air entrainmentagents in conjunction with the sacrificial agents of the invention (e.g.a combination of sodium di-isopropyl naphthalene sulfonate/ethyleneglycol phenyl ether) at increasing dosage, the air entrained is enhancedto acceptable levels. When the sacrificial agent is added at excessivedosages, the air entrained levels-off at desirable practical values.

FIG. 8 is a schematic illustration of paste air results obtained by aprotocol for assessment of the relative performance of candidatesacrificial agents, as described below. The entries identifying thevarious values are shown in abbreviated form (all dosages are expressedas wt % of cementitious materials). The abbreviation are explained asfollows:

-   -   AEA (PC): air entrainment agent at fixed dosage (DDBS, 0.0125%)        in a Portland cement paste    -   AEA (FA-PC): air entrainment agent at fixed dosage (DDBS, 0.0125        wt %) in a −50:50 fly ash:Portland cement paste    -   0.1% SA (PC): air entrainment by SA at 0.1% dosage in the        Portland cement paste    -   AEA+0.05% SA (FA-PC): air entrainment agent at fixed dosage        (DDBS, 0.0125%) plus candidate SA at 0.05% in a 50:50 fly        ash:Portland cement paste    -   AEA+0.1% SA (FA-PC): air entrainment agent at fixed dosage        (DDBS, 0.0125%) plus candidate SA at 0.1% in a 50:50 fly        ash:Portland cement paste.

FIG. 9 is a graph showing sacrificial agent performance expressed aspercentage air entrainment recovery (Delta AE) in fly ash-cement pastes(item F of FIG. 8). This data was calculated from the information inColumn 4 of Table 36 below. The data is for various aliphatic alcoholsand compares Delta AE with values of LogK_(ow) and HLB values for thesecompounds.

FIG. 10 is a graph showing sacrificial agent performance expressed aspercentage air entrainment recovery (Delta AE) in fly ash-cement pastes(item F of FIG. 8). This data was calculated from the information inColumn 4 of Table 36 below. The data is for various ethers and comparesDelta AE with values of LogK_(ow) and HLB values for these compounds.

FIG. 11 is a graph showing air entrainment recovery (Delta AE) forvarious alcohols in fly ash-cement pastes as a function of LogK_(ow)values of the alcohols.

FIG. 12 is a graph showing air entrainment recovery (Delta AE) forvarious glycol ethers in fly ash-cement pastes as a function ofLogK_(ow) values of the glycol ethers.

FIG. 13 is a graph showing air entrainment recovery (Delta AE) for allchemicals tested in fly ash-cement pastes, plotted against theirLogK_(ow) values.

FIG. 14 is a graph showing air entrainment recovery (Delta AE) for allchemicals tested in fly ash-cement pastes, plotted against their HLBvalues.

FIG. 15 is a graph showing a number of candidate sacrificial agentshaving high ratings (ratings of 3 or 4) over the LogK_(ow) scale inconsecutive ranges of 0.5 Log units.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, reference is made to air entrainment inconcrete and cementitious mixtures. It will be realized by personsskilled in the art that other inert gases, such as nitrogen, that act inthe same way as air, can be entrained in concrete and cementitiousmixtures. The use of air rather than other gases is naturally mostfrequently carried out for reasons of simplicity and economy. Techniquesfor entraining air in cementitious mixtures using air-entraining agentsare well known to persons skilled in the art. Generally, when an airentrainment agent is used, sufficient air is entrained when theingredients of the mixture are simply mixed together and agitated inconventional ways, such as stirring or tumbling sufficient to causethorough mixing of the ingredients.

As noted earlier, air entrainment problems in fly ash concrete have beentraced to undesirable components contained in the fly ash materials,particularly residual carbon. These fly ash components can adsorb and/orreact or interact with the air entrainment agent (surface activecompounds, e.g. soaps) used for entrainment air in concrete, therebyneutralizing or diminishing the functionality of such agents andconsequently reducing the uptake of air. Up to the present, theindustrial approach to dealing with these air entrainment problemsconsisted in adding higher dosages of the air entrainment agents inorder to overwhelm the deleterious processes. Because the quantities ofdetrimental components in fly ash can vary greatly among fly ashes fromdifferent sources, or for a fly ash from any particular source atdifferent times, the current practices lead to other complications,namely in assessing the adequate dosage of air entrainment agents toachieve a specified air content, in maintaining the specified aircontent over adequate time periods, in guarding against excessiveentrained air contents that would detrimentally impact concrete strengthand durability, in obtaining specified air void parameters, etc. Inparticular, the fact that excessive dosages of the air entrainment agentcan result in excess air entrainment and subsequent reduction inconcrete compressive strength, is particularly serious and a majordisadvantage of the prior approach.

To address the above problems, the inventors of the present inventiondeveloped the concept of using a different class of material (i.e.something other than an air entrainment agent) to neutralize oreliminate the effect of the harmful components of fly ash on the airentrainment agent. The inventors surmised that such a material wouldhave to act preferentially (i.e. when present at the same time as theair entrainment agent, or even after the contact of the air entrainmentagent with the fly ash, they would interact with the fly ash), and thatthey would not themselves act to entrain air in significant amounts orto harm the setting action or properties of the cementitious material inthe amounts employed. The inventors have now found certain classes ofchemical compounds (additives) capable of “neutralizing” the detrimentalfly ash components, while having little or no influence on the airentrainment process provided by conventional air entrainment agents andhaving no adverse effects on the properties of the concrete mix andhardened concrete product. Such chemical additives, referred to hereinas “sacrificial agents”, introduced into the mixture at an appropriatetime, render fly ash concrete comparable to normal concrete with respectto air entrainment. The finding of economically viable chemicaladditives of this type, as well as practical processes for theirintroduction into concrete systems, constitutes a major advantage forfly ash concrete technologies.

In order to confirm this approach to the problem and to identifysuitable additives, the inventors designed a broad research program toinvestigate the origins of air entrainment problems in fly ash concrete,and chemical solutions to alleviate these problems. The programcomprised a broad base study on pastes, mortars and concrete containingcement only and fly ash-cement mixes, with various fly ashes exhibitinga wide range of carbon contents (represented by loss-on-ignition—LOI)values and physico-chemical properties. Extensive testing was carriedout on air entrainment in fly ash concrete under standard industrialpractices; the work included studies on the impact of candidatesacrificial agents, on the properties of fresh and hardened concrete,and investigations of possible interactions between these agents andother common chemical additives (admixtures) used in concretetechnology. The experimental protocols and key results of this programare presented below and the same protocols may be employed to identifyfurther sacrificial agents suitable for use in the present invention, asdetailed more specifically in following sections.

For practical reasons, namely effectiveness, solubility in mixedformulations of sacrificial agents and cost, it has been found that thefollowing classes of compounds are the most suitable, namely: alcohols,glycol ethers, polyglycols, aromatic sulfonates, esters andalcoholamines, alkyl carboxylates, and also aromatic compounds bearingsulfonate groups, carboxylate groups, amino groups or combinations ofsuch groups, and low molecular weight glycols and glycol derivates (i.e.those having molecular weights of 2000 Da or less, preferably 1500 Da orless), and combinations of such compounds. By testing a variety ofcompounds as potential sacrificial agents, it has been discovered thatthe following compounds, in particular, are effective as sacrificialagents to varying degrees: benzylamine, sodium 1-naphthoate, sodium2-naphthalene sulfonate, sodium di-isopropyl naphthalene sulfonate,sodium cumene sulfonate, sodium di-butyl naphthalene sulfonate, ethyleneglycol phenyl ether, ethylene glycol methyl ether, butoxyethanol,di-ethylene glycol butyl ether, di-propylene glycol methyl ether,polyethylene glycol and 1-phenyl 2-propylene glycol. All of thesecompounds, and others mentioned later in this description, are known andcommercially available from suppliers of organic chemical (e.g. fromAldrich, Rutgers, Stepan, Anachemia, Baker, BDH, Eastman, Fisher,Mallinckodt, Polysciences, Pfaltz & Bauer, TCI, etc., all of which arewell known suppliers of chemicals to persons in this field of art). Theyare preferably used in pure or substantially pure form.

It has been found that these compounds may be used alone or in anycombination. However, specific combinations are particularly effectiveand synergistic effects may occur with certain combinations. Aparticularly effective combination of sacrificial agents is ethyleneglycol phenyl ether and sodium di-isopropyl naphthalene sulfonate. Whencombinations of sacrificial agents are employed, they may be used in anyrelative proportion, but the total amount employed most preferably fallswithin the range of 0.01 to 0.5 wt % of the cementitious components ofthe mixture, and more preferably 0.01 to 0.2 wt %. Because of thesurfactant properties and high effectiveness of sodium di-isopropylnaphthalene sulfonate, it is preferable to keep the amount low and touse another sacrificial agent, e.g. ethylene glycol phenyl ether, toachieve an optimum activity against the harmful components of the flyash without causing air entrainment. In such cases, the dosage of sodiumdi-isopropyl naphthalene sulfonate relative to ethylene glycol phenylether is preferably within the range of 1:20 to 1:2, respectively, byweight. In some cases, it may be advantageous to mix a sacrificial agenthaving different HLB values (e.g. high and low values) to produce acombined sacrificial agent mixture that is approximately neutral in itseffect on the entrainment of air in the mixture. In this way, it may bepossible to use highly active sacrificial agents that would otherwiseinterfere too much with the entrainment of air.

The amounts of such sacrificial agents should be sufficient topreferentially neutralize the harmful components of the fly ash thatadsorb or react with the air entrainment agents. The required minimumdosage may be determined experimentally through air entrainmentprotocols since, as discussed earlier and shown below, the deleteriouseffects of fly ash components are not directly related to their carboncontent or LOI. However, it is a particular advantage of the presentinvention that the sacrificial agents may be used in reasonable excessover the neutralizing amounts without entrainment of excess air (orreduction of such entrainment) or harming the concrete mixture or thesubsequent setting action or properties of the hardened concrete. Thismeans that an amount can be determined which exceeds the neutralizingamount required for a fly ash containing the highest amount of theharmful components likely to be encountered, and this amount can then besafely used with any fly ash cement mixture. Typically, as noted above,the minimum amount of sacrificial agent employed is usually about 0.01%by weight of total cementitious materials (cement and fly ash).

The sacrificial agents of the present invention may be added at any timeduring the preparation of the concrete mix, but are preferably addedbefore or at the same time as the air entrainment agents so that theymay interact with the fly ash before the air entrainment agents have anopportunity to do so. The mixing in this way may be carried out atambient temperature, or at elevated or reduced temperatures if suchtemperatures are otherwise required for particular concrete mixes. Thesacrificial agents may also be premixed with the fly ash or with the airentrainment agent.

It is particularly convenient to premix the sacrificial agent with thefly ash because the sacrificial agent may commence the interaction withthe harmful components of the fly ash even before the cementitiousmixture is formed. The sacrificial agent may simply be sprayed orotherwise added in liquid form onto a conventional fly ash and left tobe absorbed by the fly ash and thus to dry. If necessary, thesacrificial agent may be dissolved in a volatile solvent to facilitatethe spraying procedure. Fly ash treated in this way may be prepared andsold as an ingredient for forming fly ash cement and fly ash concrete.

Surprisingly, it has also been found that the sacrificial agent is eveneffective when added after the mixing of the other components of thecementitious mixture (including the air entrainment agent). Theinventors cannot explain this observation but it appears that thesacrificial agent may reverse any preliminary deactivation of the airentrainment agent caused by contact with the fly ash, and thusreactivate the air entrainment agent for further air entrainment. It isobserved, however, that the beneficial effect of the sacrificial agentsis somewhat lower when added at this stage rather than when added beforeor during the mixing of the other components.

As noted above, an important feature of the present invention is thatthe chemical additives used as sacrificial agents are not required to beeffective air entrainment agents in the amounts employed, so that theydo not contribute directly to air entrainment and can thus also be usedin normal concrete containing no fly ash. This confers on thesacrificial agents the particularly important feature that thesesacrificial agents can be introduced at dosages higher than the minimumdosage required to restore normal air entrainment without leading toerratic air entrainment and excessive air entrained levels. If one ofthe sacrificial agents used in a combination of sacrificial agentsexhibits some surfactant (air entrainment) properties, it shouldpreferably be proportioned in such a way that the combination ofsacrificial agents will entrain less than 2% air (more preferably lessthan 1% air, and ideally substantially no air), above the controlvalues, in normal concrete without any fly ash. That is to say, when aconcrete formulation is produced without fly ash, but with an airentrainment agent, the extra amount of air entrained when a sacrificialagent is added represents the extra air entrained by the sacrificialagent. The amount of air entrained in a cementitious mixture can bemeasured by determination of specific gravity of the mixture, or othermethods prescribed in ASTM procedures (ASTM C231, C173, C138—thedisclosures of which are incorporated herein by reference).

Typical concrete air entrainment agents are n-dodecylbenzene sulfonatesalts (referred to as Air 30) and tall oil fatty acid salts (referred toas Air 40). The typical dosage range of these ingredients in portlandcement concrete mixes is 0.002 to 0.008 wt % of the cementitiouscomponents, resulting in the entrainment of 6-8 vol % air.

Other essential components of the cementitous mixtures of the presentinvention are water, cement and fly ash. These may be used inproportions that depend on the type of material desired (e.g., pastes,grouts, mortars, concrete) and on the required fresh and hardenedproperties of the finished material. Such systems and their composition,as well as equipment and protocols for their preparation, are well knownin the art; for mortars and concrete, these are adequately described instandard reference texts, such as ASTM Cement and Concrete (e.g., 4.01,4.02); Design and Control of Concrete Mixtures—Portland CementAssociation; and American Concrete Institute—Manual of Concrete Practice(the disclosures of which are incorporated herein by reference). Forpastes, the composition and preparation equipment and protocols will bedescribed in detail in following sections. In practice, the content ofvarious ingredients in a cementitious mixture are often reported asweight ratios with respect to the cement or to the total cementitiousmaterials when other cementitious materials such as fly ash, slag, etc.,are present. These ratios are well known to persons skilled in the art.

Once formed, the cementitious mixture of the present invention may beused in any conventional way, e.g. poured into a form and allowed toharden and set. The hardened product will contain fly ash and entrainedair, but no excess of air entrainment agent that could adversely affectthe air content and properties of the hardened product.

The cementitious mixtures of the invention may include other standard orspecialized concrete ingredients know to persons skilled in the art.

First Protocol to Identify Additional Sacrificial Agents

While the present disclosure mentions several classes of sacrificialagents, as well as several individual compounds, that are effective inthe present invention, other compounds and classes of compounds may alsobe effective. To enable ready identification of such compounds andclasses of compounds, the following protocol has been developed.

-   -   1. Determine the solubility of the candidate chemical in        cementitious systems (alkaline fly ash slurries, or fly ash        cement pastes), containing different fly ashes having various        levels of the deleterious components, according to the methods        described in Example 1 below; under conditions such as those        pertaining to the data in Table 5 below. Chemicals with        potential value as sacrificial agents should be partly soluble        so that they can retain their inherent activity.    -   2. Determine the level of interaction/reaction between the        candidate sacrificial agent with the deleterious components of        the fly ash, particularly the carbon, again under conditions        pertaining to the data in Table 5 below. Potentially valuable        candidates will show partial adsorption onto the fly ash which        contain deleterious components towards air entrainment.    -   3. Under conditions pertaining to the data for Tables 6-11        below:        -   Evaluate the level of air entrainment by the candidate in            portland cement paste; preferably the candidate should            entrain low levels of air by itself (as in Table 6 below).        -   Determine if the candidate sacrificial agent has            interactions (interference or synergy) with typical concrete            air entrainment admixtures in portland cement pastes (as in            Table 8 below)    -   4. Suitable candidates will show little or nor air entrainment        by themselves and little interference on the function and        performance of the conventional air entrainment admixture.    -   5. Determine how effective the candidate sacrificial agent may        be at reducing variability in air entrainment by a conventional        AEA in fly ash—cement pastes; under conditions pertaining to the        data in Tables 7-11 below, evaluate paste air entrainment in        pastes containing a variety of fly ash having a wide range of        properties and residual carbon. Valuable candidate SA will show        both, increased air entrainment in more ‘difficult’ mixtures and        a substantial reduction in the variability of the air entrained        in the different fly ash-cement pastes (at constant fluidity);        typically the relative standard deviation on entrained air        values within the set of pastes should be reduced by 50% or        more.    -   6. Under conditions pertaining to data in Tables 8-11 below,        investigate potential synergy between the candidate SA and other        known SA's and conventional air entrainment admixtures. Such        synergy will be manifested by higher air contents in the most        difficult systems and a further reduction in the variability of        air entrainment among mixtures containing different fly ash.    -   7. Promising candidates must then be tested and confirmed in fly        ash mortars and/or concrete under conditions such as those        described for the data in Tables 14-35 below. Useful SA will        exhibit the following features:        -   enable adequate levels (typically 5-8 vol %) of air to be            entrained in concrete or other cementitious products, with            dosages of conventional air entrainment agents that are            typical of those required when no fly ash, or fly ash with            low carbon content, is used;        -   entrain predictable air levels into fly ash-concrete            regardless of the variability in the fly ash material, such            as the source, carbon content, chemical composition;        -   exhibit no interference with cement hydration and concrete            set time;        -   induce no significant changes to other physical and            durability properties of concrete;        -   are not significantly affected by the presence of other            concrete chemical admixtures, for example, water reducers,            superplasticizers and set accelerators; and cause no            detrimental effects when added in excessive dosages, such as            excessive air contents, extended set times, or strength            reduction.

Second Protocol to Identify Additional Sacrificial Agents

While the first protocol described above yields reliable evaluations ofthe relative merit of various groups of sacrificial agents, and hasproduced the results shown in Examples 1 to 31 below, the protocol isvery labour intensive, time- and material-consuming. To alleviate theseproblems, a second testing protocol has been devised, based upon theresults already collected in Examples 1 to 31.

In order to rapidly screen a large number of potential candidates foruse as fly ash concrete sacrificial agents, a second protocol has beendevised using the paste air measurement equipment and proceduredescribed later in this description, in the section entitled “Examplesrelating to Air entrainment in cement or FA:cement pastes—Maximum airprotocol”. This second protocol was designed to test the usefulness of acandidate sacrificial agent (SA) through a minimum number of paste airmeasurements, comprising, typically, the following air entrainment (AE)measurements, using a reference concrete air entrainment agent (AEA):

-   -   AE by SA in a portland cement paste    -   AE by a standard AEA in a portland cement paste    -   AE by a standard AEA in a FA-cement paste    -   AE by a standard AEA in FA-cement paste at two SA dosages

Description of Second Sacrificial Agent Testing Protocol

The second sacrificial agents evaluation protocol has been designed toassess the relative potential value of candidate sacrificial agents witha maximum of five paste air measurements.

The first two measurements (of entrained air) are carried out with astandard AEA in a portland cement paste and in a FA:cement paste; thesetwo tests provide reference values which can be used for the relativeassessment of a series of sacrificial agents. The other three paste airmeasurements pertain to the properties and effectiveness of thesacrificial agents. Hence, once the reference AEA values are determined,the potential merit of a candidate SA can be assessed from only threepaste air measurements.

Details of the systems and procedures used are given below, the resultsof which are illustrated schematically in FIG. 8 of the accompanyingdrawings.

Reference AE Measurements in Cement and FA:Cement Pastes

1. Measurement of the air entrained by a standard air-entrainingadmixture in a cement paste of fixed composition and fluidity; thelatter is a reference system which provides ‘reference’ air entrainmentvalues (‘A’ in FIG. 8). For this reference system the followingconditions were adopted (such conditions can be optimized to best suitthe particular materials and AEA admixture used):

-   -   Water: approx 200 g (adjusted to achieve fixed fluidity as given        below)    -   Cement (A): 400 g    -   Ratio w/c: 0.43 to 0.44    -   Air entrainment agent: Sodium Dodecylbenzene sulfonate (DDBS)    -   Air entrainment agent concentration: 0.0125 wt % (cementitious)    -   Paste fluidity: adjusted to yield mini-slump spread diameter        (see later) of 105±5 mm

2. Measurement of the air entrained in a 50:50 FA:cement paste by DDBSat the same dosage and under the same condition as given in 1 above; theobserved AE value will serve as a second reference value throughout theseries of tests, and it is illustrated as ‘B’ in FIG. 8. The differencebetween ‘B’ and ‘A’ in FIG. 8 is the reduction in air entrainment due tothe presence of the fly ash; this is illustrated as ‘C’ in FIG. 8.

In the present SA testing and evaluation protocol, the fly ash selectedshould remain the same for the entire set of additives tested, in orderto provide reliable relative performance ranking. For the present seriesof test, the Fly Ash selected was the one identified as B1 in Table 1below; the physico-chemical properties of this fly ash are reported inTable 1.

AE Measurements to Assess Performance of Sacrificial Agents

In testing for the relative performance of the sacrificial agent, thesacrificial agent dosage was chosen in the range 0-0.1 wt %, whichcorresponds to typical dosage values observed in paste, mortar andconcrete tests reported in Tables 2, 3 and 4 and Tables 7 to 34.

Also, in the concentration range in which they are used, SA should notinterfere markedly with the performance of AE admixtures; hence the airentrainment by SA alone in cement pastes should also be measured attheir maximum expected practical dosage. For most sacrificial agents ofthe present invention, the maximum practical dosage will be of the orderof 0.2% by weight of cementitious material, and most typically 0.1% bywt cementitious; for sacrificial agents which exhibit some concrete airentrainment by themselves, the maximum dosage may be limited to lowervalues.

The following paste air entrainment measurements will then enable aprimary assessment of SA candidate

3. Measurement of the air entrainment of the SA, by itself, in acement-only paste at a dosage of 0.1 wt %; this is illustrated as ‘D’ inFIG. 8.

4. Measurement of the air entrained by DDBS in the FA-cement pastecomprising 0.05% wt SA, under the same conditions as described in 2above. The air entrainment value observed in this system, compared tothat observed in the absence of the SA, yields the air recovery due tothe SA, and is illustrated schematically as ‘E’ in FIG. 8.

5. Same as in 4 above, but with a higher SA concentration at 0.1 wt %;the air entrainment observed, again compared to the value observed inthe absence of the SA, yields a second value of air recovery by the SAand is illustrated as ‘F’ in FIG. 8.

While it is preferable to carry out both of steps 4 and 5, a single stepcan be carried out at a single concentration of SA (e.g. 0.1 wt %) ifrequired to simplify the procedure.

As noted above, this second testing protocol will provide a relativeassessment of the potential of a series of compounds, all tested underthe specified set of conditions, using the specified materials,equipment and protocols throughout the series of test. For example,changes in the cement source, the fly ash used, the air entrainmentagent type and concentration may alter the tests results, as was shownusing the first testing protocol described earlier (see results inTables 7 to 34 of Examples below). However, compounds found effective inthis protocol should also be effective in other conditions, although thelevel of effectiveness may change. Conversely, compounds foundineffective according to this protocol should be ineffective in otherconditions.

Required Properties of Sacrificial Agents and Selection Criteria forCandidate Products Properties of Ideal Sacrificial Agent

The properties of an ideal sacrificial agent (SA) for air entrainment infly ash concrete are readily identified from specific requirements ofthe application (as outlined in the first protocol). From a performancestandpoint, the ideal sacrificial agent should exhibit:

-   -   Minimum air entrainment by itself, in cementitious systems, at        the normal application dosage.    -   Full recovery of the air entrainment reduction due to fly ash        carbon.    -   Minimal influence of SA overdosage, within a reasonable range,        on air entrainment; this allows voluntary overdosage to        compensate for variation in the fly ash carbon or other        properties;    -   Minimal influence on air void parameters (air void average size,        distribution, average spacing).    -   Minimal influence of the SA, at its normal dosage, on other        concrete properties, e.g., setting time, slump, slump loss as        function of time, bleeding and segregation.

Other desirable (but secondary) properties, which may also be consideredfor a large scale application include:

-   -   Significant solubility in water, or in liquid formulations    -   Low vapour pressure so that the SA is not lost significantly to        evaporation before use    -   Minimum deleterious effects with respect to human health and        environment (i.e. it is preferable to use SAs that are known to        be safe compounds)    -   Low cost.

Selection Criteria for Sacrificial Agents

For the purpose of rating the relative performance of various SA,initially neglecting considerations on ‘other desirable properties’ asoutlined above, two types of criteria can be used:

-   -   Qualitative rejection criteria and    -   Quantitative performance criteria

Qualitative Rejection Criteria

The following conditions would preclude the use of a particular SA:

-   -   The candidate SA has either a non significant effect, a nil        effect, or a negative effect, i.e., de-foaming effect.    -   The candidate SA entrains an excessive amount of air, by itself,        at the dosage of its intended usage.

Any SA candidate rejected under these two criteria could potentially beused in conjunction with other SA candidate to achieve the quantitativeperformance criteria described below. The general principle allowingsuch product combinations will be outlined below in the Sectionentitled: RELATIONSHIP BETWEEN THE PERFORMANCE OF SACRIFICIAL AGENTS ANDTHEIR MOLECULAR PARAMETERS.

Quantitative Performance Criteria and Rating

The candidate sacrificial agents tested were rated according to thelevel of air entrainment recovery they exhibit, through the paste airtesting protocol described above. For the relative performance rating ofthe group of products chosen as potential SA and listed in Table 36, thefollowing rating scheme (Tables A and B) was adopted (referring to FIG.8 and quantities defined therein):

TABLE A Col. 1 Col. 2 AE recovery to cement Recovery by 0.05% SARecovery by 0.1% SA paste value (E in FIG. 8) (F in FIG. 8) (C in FIG.8) <50% of C Rating 0 Rating 0 50-100% of C Rating 1 Rating 1 >100% of CRating 2 Rating 2

TABLE B Overall performance rating: Sum of ratings from air entrainmentrecovery values (col. 1 and col. 2 in Table above) Rating Overallperformance 0 Fail 1 Poor 2 Good 3 Preferred 4 Most preferred

Using this rating scheme, the potential value of each candidate SA isthus rated with a single-digit number ranging between 0 and 4. Examiningthe ratings attributed to the various chemicals tested (Table 36, col.5), it is readily seen that valuable sacrificial agents with highratings (e.g., 3 or 4) are found in many families of chemical compounds,namely: alcohols, glycol ethers, carboxylic acids, aromatic sulfonates,esters, amines, alcohol amines, amides, quaternary ammonium salts andpolyglycols. For the entire group of 104 compounds tested, the followingbreakdown is observed:

Listed below are the different groups of compounds according to theirratings—best: 4, worst: 1; all acid compounds were tested in the form ofsodium salts:

-   -   Rating 1 (13 compounds): n-Propanol, i-Propanol, Hexanol,        Sorbitol, Ethylene Glycol Methyl Ether, Methyllaurate,        Ethylcaproate, Phenyl acetic acid, 2-Naphthoic acid,        2-(2-Aminoethoxy)ethanol, tri-Ethylene Glycol, 2-Butanone        (Methyl ethyl ketone), n-Vinyl-2-pyrrolidinone.    -   Rating 2 (11 compounds): Glycerol, p-Dimethoxybenzene,        Methyloctanoate, Methylpalmitate, Methyloleate, Ethylene glycol        mono-ethyl ether acetate, Aniline, Urea, Dimethylurea, Methyl        isobutylketone, Butyraldehyde.    -   Rating 3 (15 compounds): 1-Pentanol, Neopentanol, Benzyl        alcohol, Phenyl ethyl alcohol, Ethylpropionate, Ethylbutyrate,        4-Ethyl benzene sulfonic acid, 2-Naphthalenesulfonate Na,        p-Toluene Sulfonic acid, Benzyl amine, Di-isopropanolamine,        Tetrapropyl ammonium hydroxide, Tetrabutyl ammonium chloride,        Polyethylene glycol 200, 1-Ethyl-2-Pyrrolidinone.    -   Rating 4 (25 compounds)    -   1-Butanol, 2-Butanol, t-Butanol, 3-Pentanol, Ethylene Glycol        Ethyl Ether, Ethylene Glycol n-Propyl Ether, Ethylene Glycol        n-Butyl Ether, Ethylene Glycol iso-Butyl Ether, Ethylene Glycol        Phenyl Ether, Propylene Glycol Phenyl Ether, di-Propylene Glycol        mono Methyl Ether, di-Ethylene Glycol Butyl Ether, Ethylene        Glycol di-Methyl Ether, Hexanoic acid, Tween® (POE (20) Sorbitan        monolaurate), Methylnaphthalene sulfonate Na, Triethylamine,        n-butyl amine, Tri-iso-propanolamine, n-butyl urea, Polyethylene        glycol 400, Polyethylene glycol 2000, tri-Propylene glycol,        Polypropylene glycol 425, P(EG-ran-propylene-glycol) 2500.

It is to be noted that compounds rated ‘zero’ are consideredunacceptable for use as single SAs, but could be used in mixtures withother compounds rated higher to produce a combined sacrificial agentthat is effective in the invention. Also, while SAs should themselvesentrain less than 2 vol % air (Volume D of FIG. 8), candidate compoundsfor which Volume D is greater than 2 vol % may be considered (if VolumeE and/or F is sufficiently high) for use in combination with othercompounds for which Volume D is lower, thereby providing an averagevolume of air entrainment due to the sacrificial agent of less than 2vol %.

Compounds found effective according to the second protocol may besubjected to an abbreviated version of the first protocol to determinethe most preferred compounds and effective dosages, etc.

Relationship Between the Performance of Sacrificial Agents and TheirMolecular Parameters

As noted above, valuable SA were found in many functional classes ofchemical compounds. This finding indicates that the specific nature ofthe functional group of the SA is perhaps not the prevailing (or only)factor in determining the performance of a SA. Without wishing to bebound to any particular theory, based upon the assumed mode of action ofSA in fly ash concrete, i.e., competitive adsorption of the SA and AEA,a second molecular feature which may be important, is their ‘hydrophobiccharacter’. This particular feature of chemical compounds isquantitatively defined by their ‘Hydrophilic Lipophilic Balance’ (HLB)rating, or their oil/water (or octanol/water) partition coefficients(K_(OW)).

The HLB Scale

The HLB concept and its application in colloid chemistry are describedin References 4 and 5 listed at the end of this specification (thedisclosures of which references are incorporated herein by reference),and may be understood as follows. A given molecule, comprising ahydrophilic (water-soluble) group and a lipophilic (hydrophobic) moiety,will exhibit an overall character which depends on the relativemagnitude of its hydrophilic and hydrophobic groups. The HLB scaleprovides a measure of this mixed character; the HLB scale typicallyvaries between 0 and 20, the more hydrophilic the molecule, the higherthe HLB value.

The HLB was initially designed to characterize the relative ability ofsurfactants to emulsify oil in water, or vice-versa (Reference 6).Typically, the HLB value of a non-ionic surfactant could be estimated asthe weight fraction of the hydrophilic portion of the surfactantmolecule, divided by 5 to yield a smaller, more convenient range of HLBnumbers. References 5 and 6 show how to determine HLB valuesexperimentally; for non-ionic polyol ester surfactants, the experimentalHLB value is obtained as:

HLB=20 (1−S/A) where S is the saponification number of the ester, and Ais the acid number of the recovered acid.

While the HLB procedure was designed for surfactants, it was laterextended to other organic molecules. This was achieved by assigning HLBvalues to different fragments and functional groups of surfactantmolecules, based on experimental data for families of surfactants. Thedifferent ‘group contributions’ could then be used to calculate HLBvalues for other molecules comprising the same groups. This approach isdescribed in general terms in standard textbooks (Reference 7) and isdiscussed in details by Davies (Reference 8) and McGowan (References 9and 10); these authors provide tables of HLB group contributions andadditivity schemes for calculating molecular HLB values. The calculatedHLB values are reasonably accurate for most non-ionic molecules; in somecases, for example, molecules with multiple functional groups, ormolecules with an ionic group, the accuracy of the calculated valueswill be affected (Reference 10). Because of these limitations, severalcompounds examined here could not be attributed meaningful HLB values.

Example of HLB Calculation:

Using the McGowan HLB group contribution scale (Reference 9), an exampleof HLB calculation is given below for Ethylene Glycol Phenyl Ether (orEthanol, 2-phenoxy-, or 2-Phenoxyethanol); formula: C₆H₅OCH₂CH₂OH.

The table of HLB contributions assigned to various functional groups andmolecular fragment is presented below (Table C). The fragments whichcomprise the EGPE molecule are identified in the first column, togetherwith the number of each fragment or group. The calculated HLB is simplythe sum of the group contributions listed in the last column. For EGPE,the calculated HLB value is found as 6.239.

TABLE C Scale of HLB contributions assigned to various molecular groupsin the McGowan additivity scheme (Reference 9) Number of groups HLBCalculation Hydrophilic groups Empirical HLB 7 7 —OSO3⁻ 12.05 0 —SO3⁻12.25 0 —COO⁻ 12.66 0 —COO— ester 2.28 0 —COOH 2.09 0 1 OH (free) 1.121.12 1 —O— ether 1.3 1.3 >C═O 0.972 0 —CONH2 1.953 0 —CONH— 2.136 0—CONH< 2.319 0 —CON(CH3)2 1.003 0 —CH(NH₃ ⁺)COO⁻ 4.28 0 >N+< (quater)9.4 0 >N− (tertiary) 9.18 0 >NH 8.89 0 —NH2 8.59 0 —N(CH3)2 7.53 0—N⁺(CH3)3 6.98 0 C5H5N+ (pyrridonium) 6.84 0 Lipophylic groups —CH<−0.295 0 2 —CH2— −0.475 −0.95 —CH3— −0.658 0 —CH═ −0.402 0 >C< −0.109 01 Phenyl- −2.231 −2.231 naphthyl- −3.475 0 HLB 6.239 (HLB = Sum of 7 +1.12 + 1.3 − 0.95 − 2.231 = 6.239)The Oil/Water (or Octanol/Water) Partition Coefficients K_(OW)

The hydrophobic-hydrophilic character of a molecule is also evidenced byits relative solubility in oil (octanol) and water, i.e. the ratio:solubility in oil (octanol)/solubility in water. This ratio can bemeasured directly from the equilibrium partitioning of the compoundbetween oil (octanol) and water, and expressed as the equilibriumpartition coefficient: K_(OW). Highly hydrophobic compounds, being veryoil-soluble, will exhibit high values of K_(OW); conversely, hydrophiliccompounds will exhibit low K_(OW) values. For convenience, the values ofK_(OW) are reported on a logarithmic scale as logK_(OW). Unlike the HLBscale which best applies to non-ionic surfactant-type molecules, thelogK_(OW) classification can include most types of compounds.

Experimental values of K_(OW) are available for a variety of compounds(as disclosed in References 11 to 13 listed at the end of thisspecification). As with HLB values, the experimental data was used toassigned group contributions to various portions of molecules. Fromthese assigned group values and additivity rules, values of K_(OW) canbe calculated for a wide variety of molecule of known composition andstructure (as disclosed in References 11 to 13 listed at the end of thisspecification).

Example of K_(ow) Calculation

The procedure for calculating a K_(OW) value using the K_(ow)Win programavailable from Reference 11 is illustrated below for Ethylene GlycolPhenyl Ether (EGPE). The KowWin program for predicting LogK_(ow) valuescan perform its calculation with either of the following inputs: 1—theChemical Abstract (CAS) Registry number for the molecule of interest, or2—the structure of the molecule, depicted in the ‘SMILES’ notation,which is explained in the K_(ow)Win program. For EGPE, the followinginformation can be supplied:

Compound: Ethylene Glycol Phenyl Ether (or Ethanol, 2-phenoxy-, or 2-Phenoxyethanol)

Chemical formula: C₆H₅OCH₂CH₂OH

SMILES structural representation: O(c(cccc1)c1)CCO;

Chemical Abstract Registry Number (CAS): 000122-99-6

The output of the K_(ow)Win program for calculation of the EGPELogK_(ow) value is reproduced below. The programs lists the variousfragments of the molecule, the number of such fragments (Col. 2), theunit contribution to LogK_(ow) for each fragment (Col. 4) and the totalcontribution from each fragments (Col. 5). The sum of all contributionsyields the estimated LogKow as 1.10. The program further provides acomparison with experimental LogK_(ow) values when available; for EGPE,a value reported by Hansch (see table) is given as 1.16, in relativelygood agreement with the computed value.

Example of Program Computation Output

K_(ow)Win (LogK_(ow)) Log P Calculation: SMILES: O(c(cccc1)c1)CCO CHEM:Ethanol, 2-phenoxy- MOL FOR: C8 H10 O2 MOL WT: 138.17 LOGKOW v1.66 TYPENUM FRAGMENT DESCRIPTION COEFF VALUE Frag 2 —CH2— [aliphatic carbon]0.4911 0.9822 Frag 1 —OH [hydroxy, aliphatic attach] −1.4086 −1.4086Frag 6 Aromatic Carbon 0.2940 1.7640 Frag 1 —O— [oxygen, one aromaticattach] −0.4664 −0.4664 Const Equation Constant 0.2290 LogK_(ow) =1.1002 LogK_(ow) Estimated: 1.10 Experimental Database Structure Match:Name: 2-Phenoxyethanol CAS Registry Number: 000122-99-6 ExperimentalLogK_(ow): 1.16 Experimental Reference: Hansch, C. et al. (1995)The relationship between the performance of candidate sacrificialagents, expressed as the % air recovery, and the values of K_(OW)(LogK_(OW)) and HLB is illustrated in FIG. 9 for a series of aliphaticalcohols. The data show that the capacity of the different alcohols toenhance air entrainment recovery (Delta AE) in the fly ash-cement pasteis optimal in a certain range of HLB and LogK_(OW) values: while thealcohols are displayed in decreasing order of HLB, or increasing orderof LogK_(OW), the air enhancement values (Delta AE) exhibit maximumvalues at intermediate range of HLB or LogK_(OW) values. FIG. 10illustrates similar data for a series of glycol ethers and, again,maximum values of Delta AE are observed in an intermediate range of HLBor LogK_(OW) values;

The relative performance of broader series of alcohols and glycol ethersare illustrated in FIG. 11 and FIG. 12 wherein the air recovery (DeltaAE) values are plotted against the LogK_(OW) values. In both series ofcompounds, those with the highest recovery values are found in arelatively narrow range of LogK_(OW) values.

Quantitative Criteria for Ranking of Sacrificial Agents Based on TheirMolecular Parameters

The data shown for alcohols and ethers in FIGS. 11 and 12 clearly showsthat optimum_air enhancement and recovery is observed for compoundshaving LogK_(ow) values in the range of −1 to +2. For these two familiesof chemicals, this range of LogK_(OW) values thus identifies the mostvaluable sacrificial agents.

The air entrainment recovery values for all of the chemicals tested areillustrated in FIG. 13, plotted as function of LogK_(OW). Although asignificant scatter of the data points is observed, in part due to theuncertainty on calculated values as discussed earlier (particularly forionic compounds, such as aryl sulfonates), an optimum range of LogK_(OW)values is again clearly seen. For the overall group of chemicals, theoptimum range of LogK_(OW) values is somewhat broader, extending between−3 and +2; best candidate sacrificial agents are seen in the range ofLogK_(OW) values between −2 and +2.

A tentative explanation for the observation of an optimum range ofLogK_(OW) values with respect to SA performance may be suggested asfollows. SA having low values of LogK_(OW) are too water-soluble, orhydrophilic, to interact effectively with carbon in the fly ash. At theother end, SA having high values of LogK_(OW) are too oil-soluble, orhydrophobic; such compounds, typically aliphatic oils, can interacteffectively with fly ash carbon, but they also known to act asde-foamers. Hence, they do not promote, nor assist air entrainment.

A similar plot of air entrainment recovery (Delta AE) for all chemicalstested was also drawn as function of HLB values, as illustrated in FIG.14. Because of the lack of assigned HLB values to some of the functionalgroups, a few of the 104 products tested could not be assigned ameaningful HLB value. Values assigned to some of the other compounds,for example, aromatic sulfonates (labelled Aromatic SO₃), and compoundscontaining the amino group, are probably overestimated (too high). Aswith the LogK_(OW) values, there appears an optimum range of HLB valuesfor the air recovery achieved with the various compounds tested,extending between 5 and 20.

The identification of potentially valuable sacrificial agents based ontheir LogK_(OW) values is further confirmed by examining thedistribution of product ratings as function of LogK_(OW); this isillustrated in FIG. 15. In the latter, the LogK_(OW) abscissa isseparated in ranges of 0.5 Log units; from the data in Table 36, thenumber of candidate SA which achieved ratings of 3 or 4 in eachconsecutive 0.5 LogK_(OW) range is plotted as the ordinate. From thedistribution illustrated, the ‘best’ SA candidate, i.e., those withratings of 3 or 4, are seen to cluster in the same LogK_(OW) intervalvalues as identified above: from −2 to +2.

Thus, the HLB and LogKow values can be used to predict the effectivenessof compounds as sacrificial agents in fly ash cementitious mixtures.

The testing protocol and results illustrated in Table 36, and therelationship of these results to HLB and LogKow values illustrated inFIGS. 13 and 14 pertain to single SA candidates. Since in surfactantscience and technology, it is common to blend surfactants of differentHLB values to achieve a mixture having an intermediate HLB value (seeReferences 4 to 6 disclosed below), the same approach can be pursued;that is, two or more candidate sacrificial agents with different HLB (orsimilarly LogKow) values may be combined to achieve a mixed sacrificialagent having HLB, or LogKow, values within the desirable range.

The invention is illustrated in more detain in the following by means ofExamples and Comparative Examples provided below. These details shouldnot be used to limit the generality of the present invention.

COMPARATIVE EXAMPLES

In order to illustrate the problems of using fly ash in cementitiousmixtures containing air entrainment additives, a variety of mixtureswere prepared using fly ash and cement powder of different origins anddifferent common air entrainment agents, namely a tall oil fatty acidsalt (Air 40) and an alkyl aryl sulfonate salt (Air 30). The percentageair entrainment was then measured. The detailed conditions of mixturepreparation and measurement techniques and conditions to obtain theseresults are provided in following sub-sections. Two commercial Type 10(US Type-1) portland cement powders were employed—hereinafter referredto as PCA and PCC. The different types of fly ash used are shown inTable 1 below, together with the codes by which these materials areidentified and the compositions in which these fly ashes were used insubsequent tests. The fly ash used in the different tests procedures,namely pastes, mortars and concrete, are identified in Table 1. For eachfly ash used, the weight percentages of loss on ignition are reported,and are indicative of the carbon content of the fly ash. For the FA usedin paste air entrainment and other measurements in aqueous slurriesdescribed later, the following other properties are also reported:

-   -   Fly ash class: F or C    -   Fly ash type: bituminous, sub-bituminous, lignite, western    -   BET specific surface area: standard BET nitrogen surface area    -   Specific density: determined by standard Le Chatelier flask        using iso-propanol as solvent

TABLE 1 Key physico-chemical properties of the fly ash materials used invarious cementitious mixtures. Fly Ash used in Paste Specific FA used inFA BET density Mortar FA used in Concrete type Code (m²/g) (g/cm³) LOI(%) LOI (%) LOI (%) b-F B1 3.44 2.33 4.36 5.01 1.90, 2.06, 3.7, 4.70,5.74 b-F B2 1.84, 4.05, 4.81 s-C C1 5.36 2.76 1.62 0.7 0.18, 0.62 b-F C22.63 2.20 3.32 3.04 2.90, 3.70, 4.68 w-F C3 2.54 s-C D 2.40 2.60 0.250.13 s-C E1 1.3, 2.3 b-F H1 8.45 6.37 b-F H2 3.6, 4.9 w-F M1 1.54 2.350.35 0.21 b-F M2 3.43 2.20 5.34 8.78 10.35 b-F M3 4.80 2.16 11.33 3.15w-F N 2.01 2.32 0.30 F R 2.20 2.13 0.21 0.17 lignite s: Sub-bituminous;b: bituminous; w: western; C: class C; F: class FThe results of the measurements of air entrainment in various mixes,respectively pastes, mortars and concrete, are shown in Tables 2, 3 and4 below.

TABLE 2 Air entrained (vol %) in PCA cement paste with and without flyash (50:50 fly ash:cement) by 1 part (0.0125 wt %) (col. 1), 4 parts(0.05 wt %) (col. 2) and 8 parts (0.1 wt %) (col. 3) of Air 30, (Maximumair protocol, see below). Column 1 2 3 Air 30 Air 30 Air 30 1x 4x 8x FlyAsh LOI (%) (0.0125%) (0.05%) (0.1%) PCA 6 11 13 R 0.21 3 8 12 D 0.25 411 14 M1 0.35 4 9 11 C1 1.62 3 9 14 B1 4.36 0 4 8 M2 5.34 0 3 5 M3 11.330 4 7 Average (%) 2 7 10 RSD (%) 86 46 36

TABLE 3 Air entrained (vol %) in PCA mortars with and without fly ash(30:70 fly ash:cement) by 0.002 wt % Air 30 or 0.005 wt % Air 40. Mortar(30:70 fly ash:cement) Air 30 Air 40 LOI (%) 0.002% 0.005% PCA 11.4 14.3D 0.13 7.4 11.8 R 0.17 7.8 12.6 M1 0.21 1.5 5.6 C1 0.7 1.1 5.2 C3 2.543.3 5.9 C2 3.04 2.4 6.1 M3 3.15 1.9 7.3 B1 5.01 0 0.9 M2 8.78 0 0.8 H18.45 0 0.1 Average (%) 3 6 RSD (%) 107 73

TABLE 4 Air entrained (vol %) in PCA Concrete with and without fly ash(25:75 fly ash:cement) by 0.0057 wt % Air 30 (col. 1), 0.0031 wt % Air40 (col. 2) or 0.0117 wt % Air 40 (col. 3). Column 1 2 3 Concrete (25:75fly ash:cement) Air 30 Air 40 Air 40 LOI (%) 0.0057% 0.0031% 0.0117% PCA12.0 5.8 9.0 B1 1.90 6.7 1.6 B1 2.10 5.3 B1 4.70 2.0 C2 2.90 5.0 C2 3.701.4 4.3 C2 4.68 3.0 PCC 10.0 B1 2.06 5.9 B1 5.74 5.9 C1 0.18 5.8 C1 0.622.7 C2 2.90 5.8 C2 3.70 3.5 C2 4.70 2.0 H1 6.37 3.3 M2 10.35 1.6

In many of the pastes, mortars and concrete samples examined whichcontained fly ash, it was found difficult to entrain air, i.e., muchless air is entrained compared to corresponding systems containing nofly ash.

In each group (paste, mortar and concrete) large variations in thepercentages of air entrained were observed among the different types offly ash. The variability in the percentage of entrained air fordifferent fly ash-cement systems is illustrated (e.g., Tables 2 and 3)by the high values of the relative standard deviation (σ/average % air).This shows that there is a large variability in the behaviour of themixtures relative to entrained air.

Although the percentage of air entrained was generally low forhigh-carbon fly ash, some fly ash with low carbon also exhibit very lowpercentage air entrainment. This shows that the loss on ignition of aparticular fly ash is not a reliable indicator of the behaviour of thefly ash, so it is difficulty to predict an adequate dosage of airentrainment agent or admixtures.

In high-carbon fly ash, the amount of air entrained in the paste (50:50fly ash:cement) was only poorly related to the concentration of airentrainment agents and admixtures, as illustrated by the data shown inTable 2, Columns 1, 2 and 3. Thus the behaviour of air entrainment as afunction of concentration of air entrainment agent is unpredictable.

It was also noted that, at high dosages of air entrainment agents, therelative standard deviation values for pastes decrease because an upperlimit is reached at 13-14% air for all the fly ash mixtures. Such aceiling can also be observed in concrete at 12-15% air when a very largeexcess of air entrainment agent is added, regardless of the fly ash. Theproblem is that this ceiling is too high to apply an overdose of airentrainment agent in field work.

EXAMPLES

Equivalent studies to those summarised above were carried out on pastesand mixtures containing various kinds of fly ash, air entrainment agentsand sacrificial agents according to the present invention. The resultsare shown in the Tables below.

Examples Relating to Adsorption and Precipitation of Air EntrainmentAgents and Sacrificial Agents in Aqueous Fly Ash Slurries ExperimentalProtocols

Adsorption/Precipitation of Sacrificial Agents (SA) or Air EntrainmentAgents (AEA) in 10 wt % Aqueous Fly Ash Slurries at pH 12.5:

Preparation of SA or AEA solution: Aqueous solutions of the sacrificialagents were prepared at a concentration of 3 mM or 0.003M in 0.03N NaOH(pH 12.5); aqueous solutions of the commercial AEA of unknown molecularweight (Air 30 and Air 40) were prepared at 1050 mg/l correspondingapproximately to 3 mM of DDBS, which has a molecular weight of 348g/mol). The pH of the solutions were adjusted to 12.5 with NaOH.

Precipitation in slurry extract or leachate: To perform this test, FA orcement leachate were prepared in advance, by filtering two liters of a10 wt % FA, or cement, slurry in 0.03N NaOH which had been left to standunder slow agitation for 30 min; 2.5 g of the filtrate solution wasmixed with 22.5 g of the SA or AEA solution in a 50 ml polypropylenecentrifuge tube; the latter was shaken vigorously in an orbital shaker(Eberbach Corporation) for 30 min at room temperature, centrifuged for 5min and then the supernatant solution was filtered (0.45 μm). The SA orAEA content of the solution was determined using an Ultraviolet-Visible(UV) spectrometer or by COD (Chemical Oxygen Demand) measurement.

Similarly, the solubility of SA and AEA in saturated lime solution (pH12.7) were measured to evaluate the extent of precipitation of theCa-salts of the SA or AEA under these conditions. These experimentscomprise: preparing a lime solution at pH 12.7 and mixing the latterwith a solution of SA (3 mM) or AEA (1050 mg/l); the proportions wereagain 2.5 g of the lime solution and 22.5 g of the SA or AEA solution;the sample was agitated, filtered and analyzed for dissolved SA or AEAas described above for slurry leachate experiments.

Adsorption/precipitation in Fa or cement slurries: In this protocol,aqueous slurries containing 10 wt % FA or cement were prepared asdescribed above, except that in this case, the cement was added directlyinto a solution of the SA or AEA in the following proportions: 3.0 gcement or FA, and 27 g of 3 mM sacrificial agent, or 27 g of 1050 mg/lAEA; the latter were prepared in the same way as in the precipitationtest above. The residual (soluble) SA or AEA content in the solution wasalso determined by UV or COD.

Results Example 1

Adsorption (wt % Adsorbed) of sacrificial agents or air entrainmentagents in slurries containing 10 wt % PCA cement or fly ash at pH 12.5and Precipitation (wt % precipitated) in solutions extracted fromslurries containing 10 wt % PCA cement or fly ash at pH 12.5; initialconcentrations: sacrificial agents (3 mM), Air 30 and Air 40 (0.105 wt%).

Entries in parentheses: % precipitation when reacted with solutionsextracted from the fly ash slurries (Results in Table 5).

TABLE 5 LOI Fly Ash (%) BA EGPE NA ND NS Air 30 Air 40 PCA 3 (1) 79 (79)73 (74) R 0.21 24 (0)  64 (52) 65 (24) D, class C 0.25 59 (1)  84 (9) 69 (13) N 0.30 16 (11)  1 (0) 20 (0)  26 (0) 5 (0) M1 0.35 13 (11)  4(1) 90 (80) 27 (0) 11 (0)  70 (59) 70 (67) C1, class C 1.62 25 (11) 12(0) 61 (0)   84 (31) 70 (10) 89 (32) 76 (25) C2 3.32 20 (14)  6 (0) 4(0) 17 (0) 5 (0) B1 4.36 25 (12) 12 (0) 9 (0) 14 (0) 8 (0) 25 (7)  46(19) M2 5.34 23 (15) 14 (0) 9 (0) 13 (0) 8 (0) 18 (7)  30 (4)  M3 11.3323 (13) 14 (0) 12 (0)  18 (0) 10 (0)  55 (7)  66 (0) 

As can be noted from the data in Table 5, a major fraction of the airentrainment agents tested (Air 30 and Air 40), was removed from theslurry solution due to adsorption onto the fly ash and cement particles,and precipitation as insoluble salts (see entries in parentheses: %precipitated).

Under the same conditions, the sacrificial agents are not significantlyprecipitated, except for 1-naphthoic acid in the presence of the M1 flyash, where precipitation of calcium naphthoate is likely due to a highlevel of soluble Ca in this fly ash.

Because there is no significant precipitation of the SA in the fly ashleachate, the SA removed from the slurries must be removed throughadsorption onto the fly ash. Adsorption of the sacrificial agents inalkaline fly ash slurries is significant and shows several distinctbehaviours, which may be seen as:

-   -   low adsorption, increasing with increasing fly ash carbon, for        example ethylene glycol phenyl ether;    -   intermediate adsorption not related to fly ash carbon content:        for example, benzylamine and sodium di-isopropyl naphthalene        sulfonate; and    -   strong adsorption on specific fly ash materials: for example        1-naphthoic acid sodium salt, sodium di-isopropyl naphthalene        sulfonate and sodium 2-naphthalene sulfonate.

The trends observed in the behaviour of the sacrificial agents point todifferent classes of sacrificial agents which could be used to competewith adsorption of air entrainment agents in fly ash-cement pastes, orinhibit other detrimental fly ash-related processes, in the absence ofinterfering precipitation phenomena.

The observations on adsorption-precipitation behaviours clearlydistinguishes the sacrificial agents additives from air entrainmentagents surfactants; the latter are strongly adsorbed or precipitated inthe presence of fly ash (last two columns), whereas the sacrificialagents are not. To persons skilled in the art, the sacrificial agents ofTable 5 are not classified as ‘surfactants’ except for di-isopropylnaphthalene sulfonate which exhibits an inherent surface activity and issaid to both a hydrotrope and a surfactant.

Examples Relating to Air Entrainment in Cement or Fly Ash:Cement PastesExperimental Protocols

The following protocols were followed for measurements of fluidity andair entrainment of various types of pastes compositions of examplesbelow.

Preparation of pastes: Pastes were prepared by pouring 400 g ofcementitious powder in the 350-400 g of solution (water and additives)in a vessel (8.4 cm dia,×14.5 cm height) while gently stirring with aspatula; the exact quantity of water depends on the selected W/B ratio(see below); rapid hand mixing was continued for 1 minute, followed byintense stirring at 25° C. during 2 min using a hand-held mixer (BRAUNmodel MR400). The level of air entrained is dependent on the mode ofutilisation of the mixer, namely the height of the mixer from the bottomof the vessel and the length of the mixing stroke; the followingprotocols were adopted.

Minimum air protocol: The BRAUN mixer is positioned at 1.0 inch from thebottom of the mixing vessel and the up-down motion of the mixer islimited to a 1.0 inch displacement; this provided ‘minimum air’entrained air levels and is later referred to as ‘Minimum air protocol’(Results reported in Table 6, col. 1 and Table 7).

Maximum air protocol: The BRAUN mixer is positioned at 2.5 inch from thebottom of the mixing vessel and the up-down motion of the mixer islimited to a 2.5 inch displacement; this provided ‘maximum air’entrained air levels and is later referred to as ‘Maximum air protocol’(Results reported in Tables 2 and 8-11).

Fluidity measurements: For all air entrainment measurements, the initialfluidity of the paste (without additives) was controlled using the‘mini-slump’ procedure widely used for paste and grouts. In thisprotocol, a portion of the paste was transferred into the min-slump cone(a 2¼″ high, 1½″ bottom diameter, ¾″ top diameter cone); excess pastewas skimmed-off with a straight; the cone was then raised and the spreaddiameter of the paste was recorded (average of two measurements). Thefluidity is measured at 10 minutes after mixing. The paste is returnedto the batch and reserved for subsequent AE measurements. The fluidityof the paste (without SA and AEA) is adjusted by changing the amount ofwater (water/cementitious ratio) which yields a spread diameter of 115±5mm. The latter is monitored regularly.

Air entrainment measurements: For air entrainment measurements, aportion of the paste was transferred to overfill a Plexiglas cylinder(3¾ inches height, 2 inches interior diameter), which was then levelledflush to the top of the cylinder with a straight edge. The mass of thefilled cylinder, minus the weight of the empty cylinder, is thenrecorded and used to calculate the amount of air according to thefollowing formula:

${\%\mspace{14mu}{Air}} = \frac{\begin{bmatrix}{\left( {{Mass}\mspace{14mu}{of}\mspace{14mu}{mix}\mspace{14mu}{without}\mspace{14mu}{AEA}\mspace{14mu}{or}\mspace{14mu}{SA}} \right) -} \\\left( {{Mass}\mspace{14mu}{of}\mspace{14mu}{mix}\mspace{14mu}{with}\mspace{14mu}{AEA}\mspace{14mu}{or}\text{/}{and}\mspace{14mu}{SA}} \right)\end{bmatrix}}{\left( {{Mass}\mspace{14mu}{of}\mspace{14mu}{mix}\mspace{14mu}{without}\mspace{14mu}{AEA}\mspace{14mu}{or}\mspace{14mu}{SA}} \right)\;}$

This procedure was carried out at three times at 30 min. intervals (6,36 and 66 min); the paste was let to stand at rest between measurements,and was stirred gently by hand for one minute prior to the subsequentair entrainment measurements.

The following tables gives specific mixtures compositions of variouspastes used for air entrainment measurements.

Typical mixture compositions for air entrainment measurements in pastescontaining a single additive using ‘Minimum air protocol’ (results shownin Table 6, col. 1):

Wt % Composition Weight (g) actives/CM Fly ash 200 50 portland cement200 50 Air 30 solution (5.07 wt % solid) 7.89 0.1 or Air 40 solution(4.99% solid) 8.02 0.1 or SA solution (1 wt % solid) 40 0.1 WaterDepending on the water/binder ratio (W/B) required for constantspecified paste fluidity (W/B = 0.40-0.55)

Typical mixture compositions for air entrainment measurements in pastescontaining Air 30 plus a sacrificial agent using ‘Minimum air protocol’(results shown in Table 7):

Wt % Composition Weight (g) Actives/CM Fly ash 200 50 portland cement200 50 Air 30 solution (5.07 wt % solid) 7.89 0.1 SA solution (1 wt %solid) 20 0.05 Water According to (W/B) required for constant specifiedpaste fluidity W/B = 0.40-0.55

Typical mixture compositions for air entrainment measurements in pastescontaining Air 30 plus a combination of sacrificial agent; the followingexample refers to the mixture of Air 30, ND and EGPE (ratio 1/4/4,0.0125% Air 30, 0.05% ND and 0.05% EGPE) (results in Table 8, col. 10):

Preparation of a stock solution of SA and AEA: The sacrificial agentswere blended with the AEA to give the desired ratio, for example 1/4/4,using the sample weights indicated in the Table below for a stocksolution of Air 30, ND and EGPE.

Weight Concentration Component % solid (g) (wt %) Ratio Air 30 5.0711.27 0.571 1 ND 35.47 6.444 2.285 4 EGPE 100 2.286 2.293 4 Water 80Total 100 5.15

The paste compositions prepared with the combined Air 30:ND:EGPE atratios 1:4:4, for a fixed dosage of Air 30 in the paste at 0.0125 wt %,are given below. The air entrainment results are reported in Table 8,col. 10.

Component Weight (g) Fly ash 200 g ordinary portland cement 200 gMixture of SA and AEA 8.76 (0.571 wt % Air 30) Water According to (W/B)required for constant specified paste fluidity W/B = 0.40-0.55

Other combinations of air entrainment agents and sacrificial agents wereprepared as stock solutions following the procedure outlined above,adjusting the weights of the various components to achieve the desiredcomponent ratios. The paste compositions were also prepared as describedabove, keeping the cement and fly ash content fixed at 200 g each; thestock solution containing the AEA and SA at pre-determined ratios wasintroduced to achieve a final Air 30 concentration of 0.0125 wt %.

Examples of Air Entrainment Results in Pastes Example 2

Air entrained (vol %) in PCA cement paste containing 0.1 wt % (Table 6,col. 1) and 0.0125 wt % (Table 6, col. 2) air entrainment agents (Air 30or Air 40) or selected sacrificial agents alone measured under ‘Minimumair’ and ‘Maximum air’ protocols (Results in Table 6).

TABLE 6 Column 1 2 Minimum air protocol Maximum air protocol 0.1% SA orAEA 0.0125% SA or AEA Air 30 4 6 Air 40 4 9 BA 0 1 NA 0 0 ND 3 7 EGPE 01 NS 0 2

In comparison to the air entrained by the air entrainment agents (Air 30and Air 40) in the cement pastes, the sacrificial agents alone do notentrain air significantly, except for sodium di-isopropyl naphthalenesulfonate. Comparison of the air entrainment results furtherdistinguishes the sacrificial agents of the present invention fromconventional surfactants and air entrainment agents.

Example 3

Air entrained (vol %) in 50:50 fly ash:PCA cement paste by 0.1 wt. % Air30 alone and by 0.05 wt % sacrificial agents together with 0.1% Air 30(Minimum air protocol) (Results in Table 7).

TABLE 7 Fly ash LOI (%) Air 30 +BA +NA +ND +EGPE +NS R 0.21 9 5 4 3 5 6D 0.25 15 5 6 3 5 6 M1 0.35 3 11 6 5 5 4 C1 1.62 4 14 5 4 5 12 B1 4.36 35 4 4 4 4 M2 5.34 7 4 4 4 4 3 M3 11.33 6 4 5 4 4 4 Ave. (%) 7 7 5 4 4 5RSD (%) 63 57 18 18 13 54

As noted in preceding sections in the Example above, air entrainment inFA-cement (50:50) pastes, using a conventional AEA, exhibits highvariability: Air 30 alone (0.1 wt %) entrains an average of 7% air inthe different FA-cement pastes, with a relative standard deviation of63%.

In combination with most of the sacrificial agents, Air 30 entrainedsomewhat less air on the average, but the RSD was reduced considerablyin many cases; the reduction in RSD was particularly important with1-naphthoic acid, sodium di-isopropyl naphthalene sulfonate and ethyleneglycol phenyl ether, with RSD values less than 20%.

An additional important aspect of the present invention is the findingof a class of sacrificial agents which can reduce the variability of airentrainment in cementitious systems containing different fly ashmaterials with vastly different properties; particularly usefulcandidates are ethylene glycol phenyl ether, sodium di-isopropylnaphthalene sulfonate and 1-naphthoic acid.

Example 4

Air entrained (vol %) at 66 min in 50:50 fly ash:PCA cement paste by 1part of Air 30 (0.0125%) alone and different parts (or at varyingratios) of two sacrificial agents's (sodium di-isopropyl naphthalenesulfonate (ND) and ethylene glycol phenyl ether (EGPE)), (Maximum airprotocol) (Results in Table 8).

TABLE 8 Col. 3 4 5 1 2 Air 30 Air 30/ Air 30/ 6 7 8 9 10 fly ash LOI 1ND EGPE Air 30/ND/EGPE Line Ratio (%) (0.0125%) 1/4 1/4 1/1/2 1/1/41/1/6 1/2/4 1/4/4 1 PCA 6 16 8 6 13 13 14 23 2 R 0.21 3 17 11 15 17 1718 18 3 D 0.25 4 17 13 19 19 19 19 22 4 M1 0.35 4 18 10 14 16 18 17 18 5C1 1.62 3 17 10 12 14 15 15 19 6 B1 4.36 0 11 3 4 7 8 11 14 7 M2 5.34 06 1 4 6 8 9 11 8 M3 11.33 0 10 3 5 7 8 10 13 9 Ave. 2 14 7 11 12 13 1417 (%) 10 RSD 86 32 65 58 43 38 29 23 (%)

Using the ‘maximum air’ test protocol and Air 30 at a dosage typical ofthat used for air entrainment in concrete, the air entrained in the flyash-cement pastes averaged 2% with a RSD value of 86% (col. 3).

Addition of ethylene glycol phenyl ether at four (4) times the fixed Air30 dosage yields an increase in the air entrained (7%), and asignificant reduction in RSD (col. 5).

Addition of sodium di-isopropyl naphthalene sulfonate at four (4) timesthe fixed Air 30 dosage yields a significant increase in the airentrained (14%) in all fly ash:cement pastes, and an important reductionin RSD values (col. 4).

Adding selected combinations of the two sacrificial agents, ethyleneglycol phenyl ether and sodium di-isopropyl naphthalene sulfonate,yields further improvement: Higher average % air entrained and lower RSDvalues (col. 6-10).

A further important aspect of the present invention is the finding thatthe use of combinations of sacrificial agents having different molecularproperties and adsorption/precipitation behaviour further reduces thevariability in the % air in different fly ash:cement pastes.

Example 5

Air entrained (vol %) at 66 min in 50:50 fly ash:PCA cement paste by 1part of Air 30 (0.0125 wt %) combined with 4 parts (0.05 wt %) of sodiumdi-isopropyl naphthalene sulfonate (ND) and 4 parts of various other nonionic sacrificial agents (X), (Air 30/ND/X=1/4/4), (Maximum airprotocol) (Results in Table 9).

TABLE 9 LOI Di- 1-Phe 2- Di- PEG PEG Line fly ash (%) EGPE EGME EGBE ProPGME Glycerol 200 1500 1 PCA 23 18 22 17 23 16 18 20 2 R 0.21 18 17 2216 20 18 18 18 3 D 0.25 22 20 24 18 25 18 20 21 4 M1 0.35 18 17 21 16 2016 19 18 5 C1 1.62 19 20 21 18 21 18 6 B1 4.36 14 12 16 13 16 12 14 14 7M2 5.34 11 8 11 9 11 7 9 9 8 M3 11.33 13 12 17 13 15 11 9 Ave. 17 15 1915 18 14 16 16 (%) 10 RSD 23 31 24 22 25 29 30 28 (%)

Example 6

Air entrained (vol %) at 66 min in 50:50 fly ash:PCA cement paste by 1part of Air 30 (0.0125%) combined with 4 parts of sodium 2-naphthalenesulfonate (NS) and 4 parts of various other non-ionic sacrificial agents(X), (Air 30/NS/X=1/4/4), (Maximum air protocol) (Results in Table 10).

TABLE 10 Line fly ash LOI (%) EGPE PEG 1500 1 PCA 11 2 R 0.21 11 16 3 D0.25 15 19 4 M1 0.35 11 18 5 C1 1.62 9 6 B1 4.36 4 8 7 M2 5.34 3 5 8 M311.33 3

Example 7

Air entrained (vol %) at 66 min in 50:50 fly ash:PCA cement paste by 1part of Air 30 (0.0125 wt %) combined with 4 parts (0.05 wt %) ofvarious other sulfonated sacrificial agents (X) and 4 parts ofButoxyethanol (ButOH), (Air 30/X/ButOH=1/4/4), (Maximum air protocol)(Results in Table 11).

TABLE 11 Line fly ash LOI (%) ND Cumene DBNS NS 1 PCA 23 14 17 13 2 R0.21 3 D 0.25 24 18 20 18 4 M1 0.35 5 C1 1.62 6 B1 4.36 17 7 11 7 7 M25.34 11 5 7 5 8 M3 11.33Observations:

-   Table 7: Comparing average values of air entrained in the different    fly ash:cement pastes, and the corresponding RSD values, several    other sacrificial agents in the family of polyols and alcohol    ethers, used in conjunction with sodium di-isopropyl naphthalene    sulfonate, yield results similar to those found with ethylene glycol    phenyl ether.-   Table 8: Judging from the % air entrained as function of increasing    fly ash carbon, the sodium 2-naphthalene sulfonate/ethylene glycol    phenyl ether and sodium 2-naphthalene sulfonate/PEG combinations    provide some improvement, though their performance is lower than    that of sodium di-isopropyl naphthalene sulfonate/ethylene glycol    phenyl ether.-   Table 9: Again from examination of the % air entrained, the    sacrificial agents combinations involving Butoxyethanol and several    sulfonated sacrificial agents, also yield substantial improvements,    though again, their performance is lower than that of sodium    di-isopropyl naphthalene sulfonate/ethylene glycol phenyl ether    -   These observations broadly identify two preferred classes of        valuable sacrificial agents: sulfonated aromatics and glycols or        glycol derivatives; most preferred is the sodium di-isopropyl        naphthalene sulfonate/ethylene glycol phenyl ether combination.

Data from Tables 7 to 11 particularly indicate the value of two groupsof chemicals:

-   -   1—Salts of sulfonated aromatic compounds derived from benzene or        naphthalene, and bearing other alkyl residues (methyl, butyl,        iso-propyl)    -   2—Low molecular weight glycol and glycol derivatives, namely        ethers bearing an alkyl or aryl group.

Individual chemicals from other categories, such as amines (benzylamineworked well in mortars), sodium naphthoate (worked well in pastes); 20or so other products from different chemical families were screened outof the test, early in the protocol.

The two main groups of sacrificial agents identified may be looselyclassified in the family of hydrotropes (‘Any species that enhances thesolubility of another’ (in water); ‘Examples: alkyl-aryl sulfonates suchas toluene sulfonate’ (The Language of Colloid an Interface Science, Adictionary of Terms’, Laurel, L Schram, ACS Professional Reference Book,American Chemical Society, Washington, D.C., 1993). The low molecularweight glycol derivatives would also qualify as hydrotropes.

Hence, in addition to the requirements set forth by the detailedprotocol for selection of potential candidates, most of the experimentalresults indicate that successful candidates need not be surfactants, butshould exhibit ‘hydrotropic’ features.

Examples Pertaining to Air Entrainment in Mortars Experimental Protocols

Air entrainment were measured in mortars containing portland cement only(control), or a combination of portland cement and fly ash in the ratio70:30;

The mix compositions are given in the Table below and the measurementswere performed according to standard protocols described in ASTM C185-88

Wt % Components Weight (actives/CM) Fly ash 105 g 30 Ordinary portland245 g 70 cement Sand 20-30 1400 g 400 Air 30 (3.5 wt % solid) 0.9 oz/cwt0.002 or Air 40 (12 wt % solid) 0.6 oz/cwt 0.005 SA (100 wt % solid)0.175 g 0.05 Water 210-280 (To obtain a flow of 80-95% after 10 drops offlow table) W/B = 0.6-0.8

Results Example 8

Influence of selected sacrificial agents at 0.05 wt % on air entrainmentby 0.002 wt % Air 30 in (30:70) fly ash:cement mortars or 0.0017 wt %Air 30 in PCA cement mortars (Results in Table 12).

TABLE 12 0.002 +0.05 wt % wt % +0.05 wt % +0.05 wt % Fly Ash LOI (%) Air30 EGPE BA NS PCA 11.4 14.0 11.4 13.4 (0.0017%) D 0.13 7.4 14.9 13.211.4 R 0.17 7.8 13.5 13.4 12.0 M1 0.21 1.5 5.4 4.7 5.8 C1 0.70 1.1 4.73.9 4.3 C3 2.54 3.3 5.9 6.0 4.8 C2 3.04 2.4 6.9 5.9 5.9 M3 3.15 1.9 7.61.5 6.9 B1 5.01 0.0 3.6 3.0 4.0 H1 8.45 0.0 3.1 1.8 2.7 M2 8.78 0.0 2.82.1 2.8 Average (%) 2.5 6.8 5.6 6.1 RSD (%) 107 58 75 51Observations:

-   -   In mortars, air entrainment by Air 30 alone is strongly reduced        with many of the fly ash having high carbon content and several        fly ash having low carbon; the RSD value is extremely high, in        excess of 100%.    -   With combinations of Air 30 with different candidate sacrificial        agents, the average % air increases substantially, and the        variability, illustrated by the RSD values is decreased by        approximately 50% in the case of ethylene glycol phenyl ether        and sodium 2-naphthalene sulfonate.

Example 9

Influence of selected sacrificial agents at 0.05 wt % or 0.1 wt % (caseof EGPE only) on air entrainment by 0.005 wt % Air 40 in (30:70) flyash:cement mortars or 0.004 wt % Air 40 in PCA cement mortars (Resultsin Table 13).

TABLE 13 (results of col. 2 and 3 shown in FIG. 1) Column 4 5 1 2 3+0.05 +0.05 LOI 0.005 wt % +0.05 wt % +0.1 wt % wt % wt % Fly Ash (%)Air 40 EGPE EGPE BA NS PCA 14.3 14.9 16.2 14.2 14.8 (0.004%) D 0.13 11.812.8 13.2 11.2 12.6 R 0.17 12.6 13.5 15.2 12.7 13.7 M1 0.21 5.6 8.0 12.77.2 8.2 C1 0.70 5.2 6.6 12.6 5.4 7.2 C3 2.54 5.9 8.0 9.8 7.5 7.8 C2 3.046.1 8.8 12.4 6.7 7.5 M3 3.15 7.3 10.2 18.3 8.2 10.0 B1 5.01 0.9 5.4 9.34.3 5.6 H1 8.45 0.1 3.1 5.7 2.4 3.0 M2 8.78 0.8 4.9 6.7 3.9 5.0 Average5.6 8.1 12 6.9 8.0 (%) RSD (%) 73 39 32 44 39Observations:

-   -   The results obtained with Air 40 are similar to those observed        with Air 30: in the presence of the same sacrificial agents, a        significant increase in the % air entrained and a strong        reduction in the RSD values.    -   In the mortar containing PCA only, the air level is high and it        is not significantly affected by addition of the SA. The same is        true in mortars with FA which allow reasonable air entrainment,        e.g. D and R fly ash. With other fly ash where air entrainment        is low with Air 40 only, the presence of EGPE increases the        level of air entrained very substantially in all cases tested.

These observations confirm, for mortars, the findings described earlierin fly ash:cement pastes for single sacrificial agents, with commonconcrete air entrainment agents tested: the proposed sacrificial agentscan increase air content and reduce the % air variability among thedifferent fly ashes.

Examples Pertaining to Air Entrainment in Concrete ExperimentalProtocols

Air entrainment in fresh concrete mixtures were performed according toprotocols described in ASTM C 231-97 with mix proportions as givenbelow. In all concrete containing fly ash, the fly ash content was fixedat 25%. The dosage of air entrainment agents and of sacrificial agentsare reported in the various Table of results presented below.

Ingredient (per yard³ of concrete) Weight (lbs) FA 112.5 (25%) Cement337.5 River sand 1285-1335 ¾ inch crushed lime stone 1650 Water 260-300(To obtain a slump of 5-6 inches) W/B = 0.58-0.67

The sacrificial agents were added to the cementitious mixtures inseveral ways:

-   -   1) mixing together with water and air entrainment agent solution    -   2) premixed with the fly ash    -   3) post-added into the fresh concrete which already contained        the air entrainment agent.

Results Results Pertaining to the Influence of Sacrificial Agents on AirEntrainment in Portland Cement Concrete (No Fly Ash)

This section is included to demonstrate the behaviour of the sacrificialagents and combinations of air entrainment and sacrificial agents innormal PC concrete, or concrete which would contained ideal,problem-free fly ash. The results are also intended to furtherdistinguish between the properties of the sacrificial agents and thoseof the conventional air entrainment agents.

Example 10

Air entrainment by ethylene glycol phenyl ether alone at various dosagesin PCC cement concrete (no fly ash) (Results in Table 14).

TABLE 14 Air 40 ND EGPE Total SA ND/ fly Fly ash LOI Air Line % CM % CM% CM % CM EGPE Cement ash % % % 1 0.000 0.000 0.00 PCC 1.0 2 0.000 0.0100.01 PCC 1.9 3 0.000 0.015 0.02 PCC 1.7 4 0.000 0.030 0.03 PCC 2.0 50.000 0.050 0.05 PCC 2.0 6 0.000 0.075 0.08 PCC 2.1 7 0.000 0.100 0.10PCC 2.1Observations:

-   -   The addition of a sacrificial agents such as ethylene glycol        phenyl ether in cement-only concrete (without air entrainment        agents) leads to an increase of about 1% in air entrained above        the control values, even at very high dosages (line 7); such an        effect is not significant in concrete practice, and thus        ethylene glycol phenyl ether can be used even in concrete        without fly ash (an excess of ethylene glycol phenyl ether does        not effect the air entrained in cement concrete).

Example 11

Air entrainment by sodium di-isopropyl naphthalene sulfonate alone atvarious dosages in PCC cement concrete (no fly ash) (Results in Table15).

TABLE 15 Air 40 ND EGPE Total SA ND/ fly fly ash LOI Air Line % CM % CM% CM % CM EGPE Cement ash % % % 1 0.000 0.000 0.00 PCC 1.0 2 0.000 0.0010.00 PCC 2.3 3 0.000 0.003 0.00 PCC 4.1 4 0.000 0.003 0.00 PCC 3.1 50.000 0.005 0.01 PCC 4.6 6 0.000 0.005 0.01 PCC 4.8 7 0.000 0.005 0.01PCC 4.6 8 0.000 0.010 0.01 PCC 4.6 9 0.000 0.020 0.02 PCC 3.9 10 0.0000.030 0.03 PCC 3.8 11 0.000 0.040 0.04 PCC 3.9Observations:

-   -   The incorporation of sodium di-isopropyl naphthalene sulfonate        in cement-only concrete without air entrainment agents leads to        a significant increase of the entrained air, i.e., 2-3% above        control,    -   The % air increment is low compared to conventional air        entrainment agents at similar dosages and it does not vary        substantially with sodium di-isopropyl naphthalene sulfonate        concentration

In applications where air entrainment is undesirable, the dosage ofsacrificial agents having some surfactant character, such as sodiumdi-isopropyl naphthalene sulfonate, must be kept below some criticalvalues.

Example 12

Air entrainment by sodium di-isopropyl naphthalene sulfonate andethylene glycol phenyl ether together at different ratios and totaldosages in PCC cement concrete (no fly ash) (Results in Table 16).

TABLE 16 Air 40 ND EGPE Total SA ND/ fly Fly ash LOI Air Line % CM % CM% CM % CM EGPE Cement ash % % % 1 0.000 0.000 0.00 PCC 1.0 1 0.000 0.0010.010 0.01 1/8 PCC 3.5 2 0.000 0.002 0.015 0.02 1/8 PCC 3.8 3 0.0000.004 0.030 0.03 1/8 PCC 3.8 4 0.000 0.006 0.050 0.06 1/8 PCC 4.4 50.000 0.009 0.075 0.08 1/8 PCC 3.4 6 0.000 0.003 0.010 0.01 1/4 PCC 3.87 0.000 0.004 0.015 0.02 1/4 PCC 3.5 8 0.000 0.008 0.030 0.04 1/4 PCC4.1 9 0.000 0.013 0.050 0.06 1/4 PCC 3.6 10 0.000 0.019 0.075 0.09 1/4PCC 3.6 11 0.000 0.005 0.010 0.02 1/2 PCC 5.1 12 0.000 0.008 0.015 0.021/2 PCC 5.2 13 0.000 0.015 0.030 0.05 1/2 PCC 4.1 14 0.000 0.025 0.0500.08 1/2 PCC 3.9 15 0.000 0.038 0.075 0.11 1/2 PCC 3.7Observations:

-   -   As shown by the results in Table 15, the addition of two        sacrificial agents, ethylene glycol phenyl ether and sodium        di-isopropyl naphthalene sulfonate, at varying dosages and        ratios in cement-only concrete, without air entrainment agents,        was found to increase the % air entrained above the control by        2-4%,    -   The influence of the ethylene glycol phenyl ether-sodium        di-isopropyl naphthalene sulfonate combination is similar to        that of the sodium di-isopropyl naphthalene sulfonate alone so        there is no significant synergy in air entrainment by these two        sacrificial agents alone in the absence of air entrainment        agents and fly ash.

Example 13

Influence of ethylene glycol phenyl ether at various dosages on Airentrainment by Air 40 (0.003 and 0.006 wt %) in PCA cement concrete(Results in Table 17).

TABLE 17 (results shown in FIG. 2) Air 40 ND EGPE Total SA ND/ fly flyash LOI Air Line % CM % CM % CM % CM EGPE Cement ash % % % 1 0.003 0.0000.00 PCA 6.0 2 0.003 0.050 0.05 PCA 6.5 3 0.003 0.100 0.10 PCA 6.5 40.003 0.150 0.15 PCA 6.6 5 0.003 0.200 0.20 PCA 6.2 6 0.003 0.250 0.25PCA 7.5 7 0.006 0.000 0.00 PCA 8.2 8 0.006 0.050 0.05 PCA 8.1 9 0.0060.100 0.10 PCA 8.3 10 0.006 0.150 0.15 PCA 7.5 11 0.006 0.200 0.20 PCA8.0 12 0.006 0.250 0.25 PCA 7.9Observations:

-   -   The presence of ethylene glycol phenyl ether in cement-only        concrete containing an air entrainment agents leads to a slight        increase in the % air entrained values. Thus, the results show        that, in normal cement concrete (no fly ash), the addition of        increasing levels of EGPE up to rather high dosages has no        significant influence on air entrainment observed at a fixed        dosage of Air 40 (0.003 or 0.006 wt %).    -   The sacrificial agents of the present invention do not alter the        air entrainment performance of the conventional air entrainment        agents used at ‘normal’ or ‘typical’ dosages.

Example 14

Influence of sodium di-isopropyl naphthalene sulfonate together withethylene glycol phenyl ether, or with ethylene glycol methyl ether, atvarious ratios and total dosage, on air entrainment by Air 40 (0.008 wt%) in PCA cement concrete (Results in Table 18).

TABLE 18 Total Air 40 ND SA fly fly ash LOI Air Line % CM % CM % CMCement ash % % % EGPE ND/ % CM EGPE 1 0.008 0.000 0.000 0.00 PCA 7.8 20.008 0.000 0.035 0.04 PCA 6.2 3 0.008 0.018 0.035 0.05 1/2 PCA 8.5 40.008 0.035 0.035 0.07 1/1 PCA 7.0 5 0.008 0.000 0.075 0.08 PCA 6.2 60.008 0.038 0.075 0.11 1/2 PCA 6.4 7 0.008 0.075 0.075 0.15 1/1 PCA 6.2EGME ND/ % CM EGME 8 0.008 0.000 0.050 0.05 PCA 7.2 9 0.008 0.025 0.0500.08 1/2 PCA 7.5 10 0.008 0.050 0.050 0.10 1/1 PCA 6.8Observations:

-   -   In cement-only concrete containing Air 40 as the air entrainment        agent, the % air entrained does not vary significantly in the        presence of various sacrificial agents combinations: sodium        di-isopropyl naphthalene sulfonate with either ethylene glycol        phenyl ether or ethylene glycol methyl ether.    -   These results confirm that the proposed sacrificial agents, and        sacrificial agents combinations, have little or no influence on        the air entrainment properties of some commercial air        entrainment agents in cement-only concrete,    -   The performance sacrificial agents of the present invention are        not significantly affected by differences in the chemical        composition of cements PCC (previous results) and PCA (Tables 17        and 18).

Example 15

Influence of concrete chemical admixtures (Superplasticizer, SP; Waterreducer, LW and set accelerator, AC) on air entrainment in PCA concreteby Air 40 (0.008%) in the presence of ethylene glycol phenyl ether asthe sacrificial agent (Results in Table 19).

TABLE 19 Total Air 40 ND EGPE SA ND/ SP LW AC Air Line % CM % CM % CM %CM EGPE Cement % CM % CM % CM % 1 0.008 0.000 0.00 PCA 0.401 8.6 2 0.0080.065 0.07 PCA 0.401 8.0 3 0.008 0.378 0.38 PCA 0.401 8.9 4 0.008 0.7560.76 PCA 0.401 6.9 5 0.008 0.000 0.00 PCA 0.107 9.4 6 0.008 0.065 0.07PCA 0.107 9.6 7 0.008 0.378 0.38 PCA 0.107 8.3 8 0.008 0.756 0.76 PCA0.107 8.0 9 0.008 0.000 0.00 PCA 0.587 8.0 10 0.008 0.065 0.07 PCA 0.5877.9 11 0.008 0.378 0.38 PCA 0.587 7.1 12 0.008 0.756 0.76 PCA 0.587 6.3Observations:

At a fixed dosage of Air 40, the % air entrained is not significantlyinfluenced by either:

-   -   A ten-fold increase of the dosage of the SA (comparing lines 2        to 4, lines 5 to 8).    -   The simultaneous addition of various other concrete admixtures:    -   SP a PNS superplasticizer (comparing line 1 with lines 2 to 4)    -   LW: a lignin-based water (comparing line 5 with lines 6 to 8)    -   AC: a calcium-based set accelerator (comparing line 9 with lines        10 to 12)

An additional finding of the present invention is that the role ofethylene glycol phenyl ether as a sacrificial agents of the presentinvention is not substantially altered by other common concrete chemicaladmixtures. Conversely, the sacrificial agents does not affect theperformance of these other chemical admixtures.

Example 16

Influence of concrete admixtures (same as in previous Table) on airentrainment in PCA concrete by Air 40 (0.004, 0.006, 0.008 wt %) withsodium di-isopropyl naphthalene sulfonate and ethylene glycol methylether (EGME) as sacrificial agents at varying total dosage and fixed 1:2ratio (Results in Table 20).

TABLE 20 Total Air 40 ND EGME SA ND/ SP LW AC Air Line % CM % CM % CM %CM EGME Cement % CM % CM % CM % 1 0.004 0.000 0.000 0.00 PCA 0.401 7.1 20.004 0.018 0.035 0.05 1/2 PCA 0.401 3.2 3 0.004 0.025 0.050 0.08 1/2PCA 0.401 3.2 4 0.004 0.038 0.075 0.11 1/2 PCA 0.401 3.0 5 0.006 0.0000.000 0.00 PCA 0.107 7.6 6 0.006 0.018 0.035 0.05 1/2 PCA 0.107 9.0 70.006 0.038 0.075 0.11 1/2 PCA 0.107 8.5 8 0.008 0.000 0.000 0.00 PCA0.587 7.5 9 0.008 0.018 0.035 0.05 1/2 PCA 0.587 8.5 10 0.008 0.0380.075 0.11 1/2 PCA 0.587 5.8Observations:

-   -   In the presence of an alternate sacrificial agents combination        sodium di-isopropyl naphthalene sulfonate/ethylene glycol methyl        ether, the % air entrained by Air 40 is decreased in the        presence of the superplasticizer (comparing lines 1-4), but not        significantly modified by either the water reducer (LW, lines        5-7) or the set accelerator (AC, lines 8-10);    -   A slight reduction in % air entrained by the superplasticizer is        not uncommon in concrete air entrainment (lines 1 to 4) and is        easily dealt with in practice.

Further findings of the present invention:

Sacrificial agents use in conjunction with the main types of otherconcrete chemical admixtures do not lead to erratic air entrainmentbehaviours.

The sacrificial agents of the present invention are compatible withother types of concrete chemical admixtures, i.e., there is nodetrimental influence on the respective function of these admixtures.

Results Pertaining to the Influence of Sacrificial Agents on AirEntrainment with Air 40 in Concrete Containing B1-Fly Ash and PCA Cementat a Fixed Ratio of 25:75

The following examples were carried out to study the influence of dosageand ratio of most preferred SA with the same cement and FA from aconstant source but varying LOI.

Example 17

Influence of ethylene glycol phenyl ether (0.1 wt %) on air entrainmentwith Air 40 at various dosages in B1 fly ash:PCA concrete; B1 fly ash at1.94% LOI (Results in Table 21).

TABLE 21 Total Air 40 ND EGPE SA ND/ fly fly ash LOI Air Line % CM % CM% CM % CM EGPE Cement ash % % % 1 0.003 0.000 0.00 PCA B1 25 1.9 1.6 20.006 0.000 0.00 PCA B1 25 1.9 4.3 3 0.009 0.000 0.00 PCA B1 25 1.9 5.24 0.003 0.100 0.10 PCA B1 25 1.9 5.1 5 0.006 0.100 0.10 PCA B1 25 1.96.2 6 0.009 0.100 0.10 PCA B1 25 1.9 7.4Observations:

-   -   In the presence of a fly ash with a relatively low LOI, the %        air entrained with a normal Air 40 dosage (0.003 wt %) is        strongly depressed.    -   The addition of ethylene glycol phenyl ether (0.1 wt %) allows        adequate air entrainment with the lowest (normal) air        entrainment agents dosages.    -   In the presence of the sacrificial agents, the % air increases        predictably with increasing dosage of Air 40.

It is thus further confirmed that the sacrificial agents of the presentinvention perform their intended function: allow the air entrainmentagents to entrain normal levels of air, without significantlycontributing themselves to the air entrainment.

Example 18

Influence of ethylene glycol phenyl ether (0.1 wt %) on air entrainmentwith Air 40 at various dosages in B1 fly ash:PCA concrete; B1 fly ash at4.7% LOI (Results in Table 22).

TABLE 22 Total Air 40 ND EGPE SA Fly ash LOI Air Line % CM % CM % CM %CM ND/EGPE Cement fly ash % % % 1 0.003 0.000 0.00 PCA B1 25 4.7 1.8 20.006 0.000 0.00 PCA B1 25 4.7 1.6 3 0.009 0.000 0.00 PCA B1 25 4.7 2.64 0.003 0.100 0.10 PCA B1 25 4.7 3.0 5 0.006 0.100 0.10 PCA B1 25 4.73.7 6 0.009 0.100 0.10 PCA B1 25 4.7 4.5Observations:

-   -   For this relatively high LOI fly ash, the % air entrained by Air        40 alone remains low at all dosages examined (2.6%).    -   In the presence of ethylene glycol phenyl ether, the % air        increases with increasing air entrainment agents dosage, towards        approx 5%.

Example 19

Influence of ethylene glycol phenyl ether (varying dosage) on airentrainment with Air 40 (0.003 wt %) in B1 fly ash:PCA concrete; B1 flyash at 4.7% LOI (Results in Table 23).

TABLE 23 Air 40 ND EGPE Total Fly ash LOI Air Line % CM % CM % CM % CMND/EGPE Cement fly ash % % % 1 0.003 0.000 0.00 PCA 5.5 2 0.003 0.0000.00 PCA B1 25 4.7 1.0 3 0.003 0.050 0.05 PCA B1 25 4.7 2.9 4 0.0030.100 0.10 PCA B1 25 4.7 2.7 5 0.003 0.150 0.15 PCA B1 25 4.7 3.6 60.003 0.200 0.20 PCA B1 25 4.7 5.3 7 0.003 0.250 0.25 PCA B1 25 4.7 5.6Observations:

-   -   With a high-carbon fly ash. the % air entrained by a normal        dosage of Air 40 is strongly depressed (comparing lines 1 and        2).    -   Addition of increasing dosages of ethylene glycol phenyl ether        (lines 3-7) leads to a substantial increase in the % air and a        levelling-off near 6-8 vol %; this ceiling is particularly        important for practical reasons, since it guards against excess        air when overdosing the ethylene glycol phenyl ether.

Example 20

Influence of ethylene glycol phenyl ether (varying dosage) on airentrainment with Air 40 (0.007 wt %) in B1 fly ash:PCA concrete; B1 flyash at 4.7% LOI (Results in Table 24).

TABLE 24 Total Air 40 ND EGPE SA Fly ash LOI Air Line % CM % CM % CM %CM ND/EGPE Cement fly ash % % % 1 0.007 0.000 0.00 PCA 9.0 2 0.007 0.0170.02 PCA 8.7 3 0.007 0.100 0.10 PCA 9.5 4 0.007 0.200 0.20 PCA 10.0 50.007 0.000 0.00 PCA B1 25 4.7 2.4 6 0.007 0.017 0.02 PCA B1 25 4.7 4.07 0.007 0.100 0.10 PCA B1 25 4.7 5.7 8 0.007 0.200 0.20 PCA B1 25 4.78.0Observations:

-   -   The data obtained with a higher dosage of Air 40 (compared to        the previous example) shows that:    -   In cement-only concrete the % air entrained is not significantly        affected by increasing dosages of ethylene glycol phenyl ether        (lines 1 to 4).    -   Even at this higher Air 40 dosage, the % air entrained remains        low in this high LOI fly ash (line 5).    -   In the fly ash-cement concrete, increasing dosages of ethylene        glycol phenyl ether allow entrainment of air at a level close to        that in cement-only concrete (lines 5-8).

Example 21

Influence of sodium di-isopropyl naphthalene sulfonate and ethyleneglycol phenyl ether at fixed 1:3 ratio and varying total dosage on airentrainment with Air 40 (varying concentration) in B1 fly ash:PCAconcrete; B1 fly ash at different LOI (Results in Table 25).

TABLE 25 Total Air 40 ND EGPE SA Fly ash LOI Air Line % CM % CM % CM %CM ND/EGPE Cement fly ash % % % 1 0.000 0.000 0.000 0.00 PCA B1 25 2.11.2 2 0.004 0.000 0.000 0.00 PCA B1 25 2.1 1.7 3 0.008 0.000 0.000 0.00PCA B1 25 2.1 3.7 4 0.012 0.000 0.000 0.00 PCA B1 25 2.1 5.3 5 0.0000.012 0.035 0.05 1/3 PCA B1 25 3.7 4.3 6 0.004 0.012 0.035 0.05 1/3 PCAB1 25 3.7 5.8 7 0.008 0.012 0.035 0.05 1/3 PCA B1 25 3.7 7.8 8 0.0120.012 0.035 0.05 1/3 PCA B1 25 3.7 8.0 9 0.000 0.017 0.050 0.07 1/3 PCAB1 25 5.7 4.3 10 0.004 0.017 0.050 0.07 1/3 PCA B1 25 5.7 6.2 11 0.0080.017 0.050 0.07 1/3 PCA B1 25 5.7 9.0 12 0.012 0.017 0.050 0.07 1/3 PCAB1 25 5.7 8.5Observations:

-   -   At a fixed ratio of sodium di-isopropyl naphthalene        sulfonate/ethylene glycol phenyl ether (1/3), and realistic        total sacrificial agents dosages (0.05-0.07%), the % air        entrained varies smoothly with increasing Air 40 dosage,        regardless of the LOI values of the fly ash (2.1, 3.7 and 5.7%),    -   Again, overdosing of the sacrificial agents combination (lines        10-12) does not lead to excessive air contents.

An important finding of the invention is that adequate combinations anddosages of the sacrificial agents of the present invention makes itpossible to normalize the air entrainment behaviour of fly ash-concrete,regardless of the carbon content of the fly ash.

Example 22

Influence of sodium di-isopropyl naphthalene sulfonate and ethyleneglycol phenyl ether at various ratios and total dosages on airentrainment with Air 40 (0.008 wt %) in B1 fly ash:PCA concrete; B1 flyash at 4.7% LOI (Results in Table 26).

TABLE 26 (results shown in FIG. 3) Total Air 40 ND EGPE SA Fly ash LOIAir Line % CM % CM % CM % CM ND/EGPE Cement fly ash % % % 1 0.008 0 0 0PCA No FA 0 8.5 2 0.008 0 0 0 PCA B1 25 4.7 2.5 3 0.008 0 0.035 0.035 0PCA B1 25 4.7 4.4 4 0.008 0.012 0.035 0.047 1/3 PCA B1 25 4.7 6 5 0.0080.018 0.035 0.053 1/2 PCA B1 25 4.7 6.5 6 0.008 0.035 0.035 0.07 1/1 PCAB1 25 4.7 6.5 7 0.008 0.070 0.035 0.11 2/1 PCA B1 25 4.7 5.5 8 0.0080.105 0.035 0.14 3/1 PCA B1 25 4.7 4.6 9 0.008 0 0.050 0.05 PCA B1 254.7 5 10 0.008 0.017 0.050 0.07 1/3 PCA B1 25 4.7 7.2 11 0.008 0.0250.050 0.08 1/2 PCA B1 25 4.7 7.4 12 0.008 0.050 0.050 0.10 1/1 PCA B1 254.7 5.9 13 0.008 0.100 0.050 0.15 2/1 PCA B1 25 4.7 4.3 14 0.008 0.1500.050 0.20 3 PCA B1 25 4.7 3.9Observations:

-   -   The % air values obtained show that increasing dosages of ND        lead to increased air content but the latter levels-off and even        droops again when excess sodium di-isopropyl naphthalene        sulfonate dosages are added (as is the benefit of this        invention, again distinct from normal AEA for which the air        levels would continue to rise).    -   At a fixed dosage of ethylene glycol phenyl ether, increasing        the sodium di-isopropyl naphthalene sulfonate dosage to high        values leads to a slight decrease in air entrained in these        mixes (lines 1-3, and lines 5-8); this shows that sodium        di-isopropyl naphthalene sulfonate does not behave as an air        entrainment agents in the conventional sense.

A further important finding is that the sacrificial agents of thepresent invention do not lead to excessive air entrainment when used inexcess dosages, a crucial feature for the predictability of airentrainment behaviour.

Example 23

Influence of sodium di-isopropyl naphthalene sulfonate and ethyleneglycol methyl ether (EGME) at various ratios and total dosages on airentrainment with Air 40 (0.008 wt %) in B1 fly ash:PCA concrete; B1 flyash at 4.7% LOI (Results in Table 27).

TABLE 27 Total Fly Air 40 ND EGME Sa ash LOI Air Line % CM % CM % CM %CM ND/EGME Cement fly ash % % % 1 0.008 0.000 0.000 0.00 PCA B1 25 4.72.3 2 0.008 0.000 0.035 0.04 PCA B1 25 4.7 4.0 3 0.008 0.012 0.035 0.051/3 PCA B1 25 4.7 6.2 4 0.008 0.018 0.035 0.05 1/2 PCA B1 25 4.7 7.5 50.008 0.035 0.035 0.07 1 PCA B1 25 4.7 7.4 6 0.008 0.000 0.050 0.05 PCAB1 25 4.7 4.2 7 0.008 0.017 0.050 0.07 1/3 PCA B1 25 4.7 6.6 8 0.0080.025 0.050 0.08 1/2 PCA B1 25 4.7 7.1 9 0.008 0.050 0.050 0.10 1 PCA B125 4.7 6.6 10 0.008 0.025 0.075 0.10 1/3 PCA B1 25 4.7 6.7 11 0.0080.038 0.075 0.11 1/2 PCA B1 25 4.7 6.8 12 0.008 0.075 0.075 0.15 1 PCAB1 25 4.7 4.8Observations:

-   -   The % air entrained by Air 40 with the sacrificial agent        combination sodium di-isopropyl naphthalene sulfonate/ethylene        glycol methyl ether at various ratios and total dosages shows        adequate concrete air levels in most cases (5-7%),    -   At excessive dosage (e.g. line 12) the % air is slightly reduced        as observed earlier with the sodium di-isopropyl naphthalene        sulfonate/ethylene glycol phenyl ether combination (Table 26);        this again shows the absence of detrimental overdosage effect.    -   The results confirms that ethylene glycol methyl ether can also        be used as part of a sacrificial agents combination in fly ash        concrete.

Results Pertaining to the Influence of Sacrificial Agents on AirEntrainment in Concrete with Other Fly Ash and Other Cements

The following examples are an extension of the study to confirm theapplicability of most preferred SA in mixtures containing othercombinations of fly ash and cements.

Example 24

Influence of sodium di-isopropyl naphthalene sulfonate (0.0016 wt %) andethylene glycol phenyl ether at varying dosages on air entrainment withAir 40 (0.005%)) in H2 fly ash:PCC concrete; H2 fly ash at 3.6 and 4.9%LOI (Results in Table 28).

TABLE 28 (results in FIG. 4) Total Air 40 ND EGPE SA Fly ash LOI AirLine % CM % CM % CM % CM ND/EGPE Cement Fly Ash % % % 1 0.005 0.00000.000 0 PCC 8.0 2 0.005 0.0000 0.000 0 PCC H2 25 3.6 3.8 3 0.005 0.00160.000 0.002 PCC H2 25 3.6 3.8 4 0.005 0.0016 0.025 0.03 1/16 PCC H2 253.6 7.0 5 0.005 0.0016 0.050 0.07 1/31 PCC H2 25 3.6 7.0 6 0.005 0.00160.075 0.10 1/47 PCC H2 25 3.6 7.8 7 0.005 0.0000 0.000 0 PCC H2 25 4.92.5 8 0.005 0.0016 0.000 0.002 PCC H2 25 4.9 2.5 9 0.005 0.0016 0.0250.03 1/16 PCC H2 25 4.9 5.3 10 0.005 0.0016 0.050 0.07 1/31 PCC H2 254.9 5.5 11 0.005 0.0016 0.075 0.10 1/47 PCC H2 25 4.9 5.4Observations:

In this particular case, the air entrainment is increased to near‘normal’ (without fly ash) levels with very low ND:EGPE ratios andmoderate total dosage of the combined sacrificial agent.

Example 25

Influence of sodium di-isopropyl naphthalene sulfonate and ethyleneglycol phenyl ether at fixed 1:3 ratio and varying total dosages on airentrainment with Air 40 (0.012 wt %) in B1 fly ash:PCC concrete; B1 flyash at four different LOI (Results in Table 29).

TABLE 29 (Results illustrated in FIG. 5) Total Air 40 ND EGPE SA Fly ashLOI Air Line % CM % CM % CM % CM ND/EGPE Cement Fly Ash % % % 1 0.0120.000 0.000 0 PCC 9.0 2 0.012 0.000 0.000 0 PCC B1 25 2.06 5.5 3 0.0120.008 0.025 0.03 1/3 PCC B1 25 2.06 8.2 4 0.012 0.017 0.05 0.07 1/3 PCCB1 25 2.06 8.0 5 0.012 0.025 0.075 0.10 1/3 PCC B1 25 2.06 7.6 7 0.0120.000 0.000 0 PCC B1 25 3.70 3.8 8 0.012 0.008 0.025 0.03 1/3 PCC B1 253.70 6.7 9 0.012 0.017 0.05 0.07 1/3 PCC B1 25 3.70 8.0 10 0.012 0.0250.075 0.10 1/3 PCC B1 25 3.70 7.1 12 0.012 0.000 0.000 0 PCC B1 25 4.703.2 13 0.012 0.008 0.025 0.03 1/3 PCC B1 25 4.70 7.0 14 0.012 0.017 0.050.07 1/3 PCC B1 25 4.70 7.6 15 0.012 0.025 0.075 0.10 1/3 PCC B1 25 4.707.6 17 0.012 0.000 0.000 0 PCC B1 25 5.74 3.0 18 0.012 0.008 0.025 0.031/3 PCC B1 25 5.74 7.3 19 0.012 0.017 0.050 0.07 1/3 PCC B1 25 5.74 8.020 0.012 0.025 0.075 0.10 1/3 PCC B1 25 5.74 7.6Observations:

-   -   In this series of tests, the air entrainment agent dosage is        high so the % air value in cement-only concrete is high (9%),    -   The % air entrained in FA-cement concrete is not related to the        LOI in the absence of sacrificial agent.    -   Regardless of the % LOI (2.06, 3.7, 4.7 or 5.74), relatively low        dosages of the sacrificial agents combination (0.075 wt %)        yields % air entrainment values comparable to that in        cement-only concrete.

Example 26

Influence of sodium di-isopropyl naphthalene sulfonate and ethyleneglycol phenyl ether at fixed 1:3 ratio and varying total dosages on airentrainment with Air 40 (0.005 wt %) in E1 fly ash:PCC concrete; E1 flyash at two different LOI (Results in Table 30).

TABLE 30 (Results shown in FIG. 6) Total Air 40 ND EGPE SA Fly ash LOIAir Line % CM % CM % CM % CM ND/EGPE Cement Fly Ash % % % 1 0.005 0.0000.000 0 PCC 7.9 2 0.005 0.000 0.000 0 PCC E1 25 1.28 1.3 3 0.005 0.0080.025 0.03 1/3 PCC E1 25 1.28 4.9 4 0.005 0.017 0.050 0.07 1/3 PCC E1 251.28 7.4 5 0.005 0.025 0.075 0.10 1/3 PCC E1 25 1.28 8.0 6 0.005 0.0000.000 0 PCC E1 25 2.29 0.9 7 0.005 0.008 0.025 0.03 1/3 PCC E1 25 2.292.6 8 0.005 0.017 0.050 0.07 1/3 PCC E1 25 2.29 5.4 9 0.005 0.025 0.0750.10 1/3 PCC E1 25 2.29 7.0Observations:

-   -   Although the LOI values of these FA are relatively low, they        sharply reduce the % air when present in concrete (from 7.9% to        approximately 1%),

In the presence of increasing dosages of the ND/EGPE combination, the %air values are increased to values close to those in cement-onlyconcrete.

Example 27

Influence of sodium di-isopropyl naphthalene sulfonate and ethyleneglycol phenyl ether at fixed 1:3 ratio and varying total dosages on airentrainment with Air 40 (varying dosages) in C1 fly ash:PCC concrete; C1fly ash at 0.62% LOI (Results in Table 31).

TABLE 31 (results in FIG. 7) Total Fly Air 40 ND EGPE SA ash LOI AirLine % CM % CM % CM % CM ND/EGPE Cement fly ash % % % 1 0.003 0.00 PCC7.4 2 0.003 0.00 PCC C1 25 0.62 2.7 3 0.003 0.012 0.035 0.05 1/3 PCC C125 0.62 5.8 4 0.003 0.017 0.050 0.07 1/3 PCC C1 25 0.62 6.5 5 0.003 0.00PCC 6.0 6 0.007 0.00 PCC 8.7 7 0.012 0.00 PCC 9.4 8 0.000 0.008 0.0250.03 1/3 PCC C1 25 0.62 4.5 9 0.004 0.008 0.025 0.03 1/3 PCC C1 25 0.625.5 10 0.008 0.008 0.025 0.03 1/3 PCC C1 25 0.62 8.1 11 0.012 0.0080.025 0.03 1/3 PCC C1 25 0.62 9.2Observations:

-   -   With this particular fly ash, the % air entrained is strongly        depressed, in spite of its relatively low LOI value (lines 1-2).    -   Addition of increasing amounts of sodium di-isopropyl        naphthalene sulfonate and ethylene glycol phenyl ether at a        fixed ratio (1/3), allows to recover adequate entrained air        levels (lines 3-4).    -   Increasing the Air 40 dosage, at fixed content of sodium        di-isopropyl naphthalene sulfonate/ethylene glycol phenyl ether,        also yields a smooth increase of the air entrained with air        entrainment agents dosage as desired in practice (lines 8-11);        the latter increase is comparable with the air entrained in        cement-only concrete in identical conditions (lines 5-7).

Results Pretaining to the Performance of Sacrificial Agents in thePresence of Activated Carbon Added Intentionnally in the Fly Ash

The following examples show the effects of intentionally increasing thecarbon content of the fly ash by adding activated carbon; the latter mayor may not be similar to the carbon originally present in the fly ash.

In the testing referenced described below, the activated carbon used wasDARCO FGD from Norit Americas Inc. This is a lignite coal-basedactivated carbon manufactured specifically for the removal of heavymetals and other contaminants typically found in incinerator flue gasemission streams. Its use has been reported effective for the removal ofmercury in coal combustion gas streams. The material used was 95% minusa 325 sieve with general characteristics of a specific surface area of600 m²/g and an iodine number of 600 g/mg.

Example 28

Influence of sodium di-isopropyl naphthalene sulfonate and ethyleneglycol phenyl ether at fixed 1:3 ratio and total dosage (0.07 wt %) onair entrainment with Air 40 (0.004 wt %) in C1 fly ash:PCC concretecontaining activated carbon added at 0.5 and 1 wt % on fly ash; C1 flyash at 0.18% LOI, (Results in Table 32).

TABLE 32 Activated Total Carbon/fly Air 40 ND EGPE SA ND/ fly fly ashLOI Air ash Line % CM % CM % CM % CM EGPE Cement ash % % % % 1 0.0040.00 PCC C1 25 0.18 5.7 None 2 0.004 0.00 PCC C1 25 0.18 1.0 0.50 30.004 0.00 PCC C1 25 0.18 0.8 1.00 4 0.004 0.017 0.050 0.07 1/3 PCC C125 0.18 7.0 0.50 5 0.004 0.017 0.050 0.07 1/3 PCC C1 25 0.18 5.7 1.00Observations:

-   -   The addition of low amounts of activated carbon to a concrete        containing a low LOI fly ash strongly depresses the level of air        entrainment by Air 40 (lines 1-3).    -   Introduction of the sodium di-isopropyl naphthalene        sulfonate/ethylene glycol phenyl ether combination restores the        air entrainment to normal levels.

Results Pertaining to the Influence of the Mode of Addition on thePerformance of Sacrificial Agents

In previous examples, the sacrificial agents were added together withthe air entrainment agents during the concrete batching process. Thedata below relates to alternate means of addition of the sacrificialagents.

Example 29

Comparative air entrainment in B1 fly ash:PCA concrete by Air 30 or Air40 (varying dosages) and ethylene glycol phenyl ether (0.01 wt %) whenthe sacrificial agents is added either during batching or pre-mixed withthe fly ash; B1 fly ash at 4.7% LOI, (Results in Table 33).

TABLE 33 Total ND EGPE SA Fly ash LOI Air Line % CM % CM % CM ND/EGPECement fly ash % % % Air 30 % CM 1 0.006 0.100 0.10 PCA B1 25 4.7 11.4 2* 0.006 0.100 0.10 PCA B1 25 4.7 10.0 Air 40 % CM 1 0.003 0.100 0.10PCA B1 25 4.7 2.7  2* 0.003 0.100 0.10 PCA B1 25 4.7 2.9 3 0.008 0.1000.10 PCA B1 25 4.7 4.9  4* 0.008 0.100 0.10 PCA B1 25 4.7 4.7 *premixsacrificial agents with fly ashObservations:

-   -   When the ethylene glycol phenyl ether is premixed to the fly ash        material before batching the concrete, the observed % air is        comparable to that observed with the simultaneous addition of        ethylene glycol phenyl ether, with both types of common air        entrainment agents (comparing lines 1 and 2*, 3 and 4*).    -   The same observation was made for both types of common concrete        air entrainment agents Air 30 and Air 40.

Example 30

Comparison of results for sacrificial agents added during concretemixing, or after concrete mixing. The sacrificial agents combination issodium di-isopropyl naphthalene sulfonate:ethylene glycol phenyl etherat 1:15 ratio and varying total dosages; H2 fly ash:PCC concrete; H2 flyash at 3.96% or 5.7% LOI (Results in Table 34)

TABLE 34 Total Air 40 ND EGPE SA fly ash LOI Air Line % CM % CM % CM %CM ND/EGPE Cement Fly Ash % % % 1 0.005 0.000 PCC H2 25 3.96 2.4  2*0.005 0.0017 0.025 0.027 1/15 PCC H2 25 3.96 4.5  3** 0.005 0.0017 0.0250.027 1/15 PCC H2 25 3.96 5.6 4 0.005 0.000 PCC H2 25 5.70 1.9  5* 0.0050.0033 0.050 0.053 1/15 PCC H2 25 5.70 4.4  6** 0.005 0.0033 0.050 0.0531/15 PCC H2 25 5.70 5.1 *sacrificial agents added 0-15 minutes aftermaking concrete with Air 40 **sacrificial agents added together with Air40 during mixing operationObservations:

-   -   A comparison of the entries in lines 1-3, or lines 4-6, shows        that the sacrificial agents is also effective in increasing air        entrainment in fly ash concrete when added after the concrete        mixing operation is completed. In this case the % air achieved        is somewhat lower than if the sacrificial agents and air        entrainment agents are added simultaneously.    -   The sacrificial agents of the present invention can thus be        introduced at various point in the concrete fabrication process,        namely: pre-mix with the fly ash before making concrete, during        the concrete batching process, before introduction of the air        entrainment agents, together with the air entrainment agents, or        after the air entrainment agents when the concrete mixing is        completed.

Results Pertaining to Properties of Air Void Systems in Fly Ash ConcretePrepared with and without Sacrificial Agents

An important aspect of the air entrained in concrete is its distributionwithin the pastes. Standard concrete practices defined by the AmericanConcrete Institute (ACI) or ASTM provide specific requirements on‘bubble’ size, size distribution, surface area, etc. The criticalparameters of air voids obtained in air entrained concrete with andwithout sacrificial agents are reported in Table 35.

Example 31

Results of Petrographic Analysis of Air Voids Systems for several flyash concrete (Results in Table 35).

TABLE 35 ACI/ASTM specifications Fly ash None B1 B1 B2 B2 H2 H2 Fly ashLOI (%) NA 5.7 5.7 1.8 4.8 2.7 4.9 Air 40 Dosage (% CM) 0.003 0.0120.005 0.007 0.007 0.005 0.005 EGPE (% of total CM) 0 0 0.05 0 0.075 00.05 ND (% of total CM) 0 0 0.013 0 0.025 0 0.0016 Fresh Air Content (%)6.0 5.9 6.3 6.0 6.0 5.2 5.5 Air Content (%) 7.37 7.78 6.73 8.54 6.275.17 6.06 — Void Frequency (in.⁻¹) 12.77 12.43 10.35 15.13 10.24 10.4211.05 Minimum 8 Paste/Air Ratio 3.10 2.58 3.22 2.73 4.01 4.16 3.97Maximum 10 Average Chord Length (in.) 0.006 0.006 0.007 0.006 0.0060.005 0.005 — Specific Surface (in.⁻¹) 693 639 615 709 653 807 729Minimum 600 Spacing Factor (in.) 0.004 0.004 0.005 0.004 0.006 0.0050.005 Maximum 0.008 Paste Content (%) 22.87 20.04 21.67 23.28 25.1421.49 24.04 — Coarse Aggregate (%) 42.84 45.87 49.51 37.67 38.91 44.0141.94 — Fine Aggregate (%) 26.93 26.31 22.09 30.51 29.68 29.34 27.96 —Traverse Area (In.²) 14.9 14.9 14.0 14.9 14.9 14.9 14.9  11 TraverseLength (in.) 94.4 94.4 92.7 94.4 94.4 94.4 94.4  90 Total Point Counted1452 1452 1426 1452 1452 1452 1452 1350 Magnification 65 65 65 65 65 6565  50Observations:

-   -   The introduction of the sacrificial agents combination sodium        di-isopropyl naphthalene sulfonate/ethylene glycol phenyl ether        does significantly influence the air void parameters in the        concrete.

Examples Relating to Second Testing Protocol Example 32

A wide variety of chemical compounds were chosen as potentially usefulsacrificial agents and were evaluated through the second test protocoldescribed above. The results obtained for 104 chemicals tested arecollected in Table 36 and grouped by families of related compounds; forexample, alcohols, polyols, ethers, etc; the entries in Table 36 are asexplained below, and the significance of some of these entries isillustrated in FIG. 8.

-   -   Col. 1: Chemical name of compound tested as potential        sacrificial agent    -   Col. 2: Level of air entrainment by the candidate sacrificial        agent, at a concentration of 0.1 wt %, in a Portland cement        paste (‘A’ in FIG. 8)    -   Col. 3: Air entrainment by 0.0125 wt % of DDBS in the FA/cement        paste in the presence of 0.05 wt % of the candidate sacrificial        agent    -   Col. 4: Air entrainment by 0.0125 wt % of DDBS in the FA/cement        paste in the presence of 0.10 wt % of the candidate sacrificial        agent    -   Col. 5: Sacrificial agent overall rating index (described below)    -   Col. 6: Hydrophilic-Lipophilic Balance (HLB) values of candidate        sacrificial agent (source and significance of HLB data given        below)    -   Col. 7: Logarithm of the Oil(octanol)/water partition        coefficient (K_(ow)) of the candidate sacrificial agents (source        and significance of data given below).

TABLE 36 Data from paste air testing protocol for relative assessment ofvarious candidate sacrificial agents B1 + B1 + PCA + 0.0125% 0.0125% SA0.1% DDBS + DDBS + Rating SA 0.05% SA 0.1% SA (0-4) HLB Alcohols LogKowMethanol 0.6 1.9 2.2 0 7.5 −0.63 Ethanol 1.5 3.1 3.3 0 7.0 −0.14n-Propanol 2.0 3.5 4.4 1 6.5 0.35 i-Propanol 2.4 3.7 4.1 1 6.5 0.281-Butanol 1.2 5.9 6.5 4 6.0 0.84 2-Butanol 1.4 6.0 6.6 4 6.0 0.77tert-Butanol 0.8 6.3 7.0 4 6.0 0.73 1-Pentanol 0.9 4.9 4.7 3 5.6 1.333-Pentanol 0.5 6.1 6.3 4 5.6 1.26 Neopentanol 0.8 4.9 4.7 3 5.6 1.22Hexanol 0.0 4.2 2.7 1 5.1 1.82 1-Octanol 0.0 2.1 1.4 0 4.1 2.811-Decanol 0.0 2.1 1.7 0 3.2 3.79 Benzyl alcohol 0.6 4.1 5.4 3 5.5 1.08Phenyl ethyl alcohol 0.7 4.5 5.5 3 5.1 1.57 Polyols, diols EthyleneGlycol 0.0 2.4 2.8 0 8.3 −1.20 Propylene Glycol 0.5 3.0 3.6 0 7.8 −0.782,3-Butanediol 1.2 3.6 3.7 0 7.3 −0.36 Glycerol 0.1 n.a. 2.3 2 9.1 −1.65Inositol 0.1 2.1 2.1 0 11.9 −2.08 Sorbitol 0.5 2.2 4.2 1 11.6 −3.01Ethers Ethylene Glycol Methyl Ether 0.7 3.3 4.3 1 8.2 −0.91 EthyleneGlycol Ethyl Ether 1.2 5.0 6.8 4 7.3 −0.42 Ethylene Glycol n-PropylEther 1.4 7.4 7.4 4 6.9 0.08 Ethylene Glycol n-Butyl Ether 2.0 8.8 9.5 46.4 0.57 Ethylene Glycol iso-Butyl Ether 1.7 8.8 9.5 4 6.0 0.49 EthyleneGlycol Phenyl Ether 1.5 6.9 8.1 4 5.4 1.10 Propylene Glycol Phenyl Ether1.0 7.2 6.7 4 4.9 1.52 di-Propylene Glycol mono Methyl 1.1 8.7 9.7 4 7.2−0.35 Ether di-Ethylene Glycol Butyl Ether 2.7 9.9 11.2 4 6.7 0.29Ethylene Glycol di-Methyl Ether 1.5 4.9 5.8 4 7.3 −0.21p-Dimethoxybenzene 0.7 4.7 4.0 2 6.5 2.15 Esters Methylpropionate 0.22.7 3.5 0 7.5 0.86 Methyloctanoate 0.0 4.8 2.2 2 5.1 3.32 Methyllaurate1.0 4.6 2.8 1 3.2 5.28 Methylpalmitate 2.5 5.3 3.4 2 1.3 7.25Methyloleate 0.5 5.1 2.7 2 0.5 8.02 Ethyl acetate 0.8 3.2 3.3 0 7.5 0.86E.G. mono-ethyl ether acetate 0.0 4.7 4.7 2 7.7 0.59 Ethylpropionate 0.94.9 4.6 3 7.0 1.36 Ethylbutyrate 0.7 5.2 4.3 3 6.5 1.85 Ethylcaproate0.0 4.3 2.4 1 5.6 2.83 N-Butyl phthalate 0.0 2.2 2.1 0 5.0 4.61 Dimethylmalonate 0.2 2.5 2.6 0 9.8 −0.09 Tween 20 (POE(20)sorbitan 2.6 9.2 8.5 416.7 −3.4 monolaurate) Carboxylic acids and derivatives LogKow(*)Hexanoic acid 2.4 5.1 4.9 4 6.5 −1.76 Oleic acid 2.1 2.2 1.9 0 1.0 3.92Adipic acid 0.2 1.9 2.2 0 9.3 −5.03 Sodium Salicylate 0.4 2.9 3.0 0 7.8−1.49 4-Hydroxybenzoic acid 1.0 2.1 2.4 0 7.8 −2.10 2,5-Dihydroxybenzoicacid 0.0 1.9 1.6 0 9.2 −1.97 Phenyl acetic acid 0.2 2.8 4.2 1 6.3 −2.022-Naphthoic acid 1.3 3.2 4.2 1 5.2 −1.09 Aromatic Sulfonates LogKow4-Hydroxybenzenesulfonic acid 0.1 2.1 2.0 0 18.5 −3.43 4-Ethyl benzenesulfonic acid 1.3 4.8 6.2 3 16.3 −1.91 2-Naphthalenesulfonate Na 1.0 4.45.3 3 15.2 −1.78 p-Toluene Sulfonic acid 0.7 3.9 5.1 3 16.4 −2.402,6-naphthalene disulfonate Na 0.0 2.3 3.0 0 27.5 −3.51 Naphthalenetrisulfonate Na 0.2 2.5 2.5 0 39.7 −5.25 4,5-Dihydroxynaphthalene-2,7-0.0 2.0 2.5 0 29.9 −4.48 disulfonic acid, disodium salt4-Amino-3-hydroxynaphthalene 0.4 3.1 2.9 0 26.0 −3.17 sulfonate NaMethyl naphthalene sulfonate Na 7.3 6.0 8.8 4 15.1 −1.23 AminesTriethylamine 0.5 5.2 5.1 4 12.8 1.51 Tripropylamine 0.3 2.6 2.4 0 11.42.99 n-butyl amine 1.2 5.7 8.1 4 13.5 0.83 Aniline (Phenylamine) 1.7 3.75.6 2 13.5 1.08 Benzyl amine 1.1 4.5 6.1 3 12.0 1.07 AlcoholaminesDi-ethanolamine 0.3 2.7 2.6 0 16.5 −1.71 Tri-ethanolamine 0.6 2.5 3.1 016.7 −2.48 2-(2-Aminoethoxy)ethanol 0.5 3.1 3.9 1 16.1 −1.89Di-isopropanolamine 1.1 4.6 5.5 3 15.6 −0.88 Tri-isopropanolamine 1.35.6 7.6 4 15.5 −1.22 2,3-diaminopropionic acid 0.3 1.7 1.9 0 26.7 −4.46monohydrochloride Amides Urea 0.1 n.a. 2.0 2 25.2 −1.56 Dimethylurea 0.5n.a. 2.9 2 24.4 −0.62 n-butyl urea 2.1 5.3 7.5 4 23.4 0.38 Ammoniumsalts Tetramethyl ammonium hydroxide 0.1 2.5 2.9 0 14.9 −2.47 Tetraethylammonium hydroxide 0.1 2.3 3.0 0 13.0 −0.51 Tetrapropyl ammoniumhydroxide 0.6 3.9 4.8 3 11.1 1.45 Tetrabutyl ammonium chloride 0.6 4.94.1 3 n.a. 1.71 Benzyltrimethyl ammonium 1.0 2.3 3.0 0 11.9 −0.77hydroxide Polyglycols tri-Ethylene Glycol 0.9 3.1 4.1 1 9.0 −1.75Polyethylene glycol 200 0.9 4.3 5.7 3 9.3 −2.02 Polyethylene glycol 4001.0 8.1 9.6 4 11.1 −3.26 Polyethylene glycol 2000 2.1 10.2 11.5 4 n.a.n.a. tri-Propylene glycol 1.6 7.8 9.2 4 7.6 −0.50 Polypropylene glycol425 0.8 9.7 11.2 4 7.0 0.08 Polypropylene glycol 2200 0.0 1.5 1.0 0 3.24.37 P(EG-ran-propylene-glycol) 2500 2.3 9.8 12.2 4 n.a. n.a. PEO-PPO0.33:1 triblock 1.7 3.1 3.0 0 n.a. 3.52 copolymer Phosphates Sodiumphosphate dibasic 0.0 2.1 2.3 0 n.a. −5.80 Dimethylphosphate Na 1.3 2.52.7 0 n.a. −0.66 Sodium tripolyphosphate 0.2 2.2 1.9 0 n.a. −13.26Miscellaneous 2-Butanone (Methyl ethyl 0.3 3.7 4.1 1 6.2 0.26 ketone)Methyl isobutylketone (MIBK) 0.3 5.6 3.9 2 5.2 1.16 Dimethylsulfoxide0.0 2.5 3.1 0 n.a. −1.22 Ethylene carbonate 0.0 2.5 1.9 0 19.8 −0.34Propylene carbonate 0.4 2.5 2.9 0 18.9 0.08 Acetonitrile 0.5 2.3 2.5 0n.a. −0.15 Butyraldehyde 0.0 4.0 4.0 2 6.4 0.82 1-Methyl-2-Pyrrolidinone1.9 3.6 3.8 0 15.1 −0.10 1-Ethyl-2-Pyrrolidinone 2.5 4.3 5.6 3 14.6 0.38n-Vinyl-2-Pyrrolidinone 2.8 3.7 4.3 1 14.9 0.25 Alpha-Pinene 0.4 2.4 2.90 2.5 4.27 (*)Sodium salts

REFERENCES

-   1. Dodson, V., Concrete admixtures. Structural Engineering Series,    Ed. Van Nostrand Reinhold, New York, 211 pp., 1990.-   2. Rixom, R. and Mailvaganam N., Chemical Admixtures for Concrete.    3^(rd) Ed. E&FN SPON, London, Chap. 3, 437 pp., 1999.-   3. Ramachandran, V. S., Concrete Admixtures Handbook. Properties,    Sciences, and Technology. Ed. Noyes, New Jersey, 626 pp., 1984.-   4. Griffin, W. C., Classification of Surface Active Agents by “HLB”,    Journal of the Society of Cosmetic Chemists, V 1, pp. 311-326, 1949-   5. Griffin, W. C., Calculation of HLB Values of Non-Ionic    Surfactants, Journal of the Society of Cosmetic Chemists, V 5, pp.    249-259, 1954-   6. ‘The HLB Sytem, A time-saving guide to emulsifier selection’,    Ed., Chemmunique, Publication by ICI Americas Inc., 1980.-   7. Adamson A. W. and Gast A. P., Physical Chemistry of Surfaces, Ed.    John Wiley&Sons, Inc., 6^(th) ed., 1997.-   8. Davies, J. T., Proc. 2^(nd) International Congress on Surface    Activity, London, Vol. 1, p. 426, 1957.-   9. McGowan, J. C., A new approach for the calculation of    hydrophile-lipophile balance values of surfactants, Tenside,    Surfactants, Detergents, V 27(4), pp. 229-230, 1990-   10. Sowada, R. and McGowan, J. C., Calculation of    hydrophile-lipophile balance (HLB) group numbers for some structural    units of emulsifying agents, Tenside, Surfactants, Detergents, V    29(2), pp. 109-113, 1992.-   11. Meylan, W. M. and Howard, P. H., Atom/fragment contribution    method for estimating octanol-water partition coefficients, J.    Pharm. Sci. V 84, pp. 83-92, 1995. and Interactive LogKow (KowWin)    Demo, http://esc.syrres.com/interkow/kowdemo.htm, Syracuse Research    Corporation, North Syracuse, New York.-   12. Interactive PhysProp Database Demo,    http://esc.syrres.com/interkow/physdemo.htm, Syracuse Research    Corporation, North Syracuse, New York.-   13. Tetko, I. V.; Tanchuk, V. Yu. Application of Associative Neural    Networks for Prediction of Lipophilicity in ALOGPS 2.1 Program. J.    Chem. Inf. Comput. Sci., V 42(5), pp. 1136-1145, 2002, and Tetko, I.    V and Tanchuk, V. Y., http://146.107.217.178/lab/alogps/start.html,    Virtual Computational Chemistry Laboratory.

The disclosures of the above references are specifically incorporatedherein by reference.

1. A method of pre-treating fly ash or another combustible ash to reduceor eliminate the effect the fly ash or the other combustible ash has onair entrainment in an air-entraining cementitious mixture comprising thefly ash or other combustible fly ash and an air-entraining agent, themethod comprising: mixing a sacrificial agent with fly ash or anothercombustible ash to form a pre-treated ash, wherein the sacrificial agentis combined with the fly ash or the other combustible ash in at least anamount necessary to neutralize the detrimental effects of components ofthe fly ash or the other combustible ash on air entrainment activity inthe air-entraining cementitious mixture, the sacrificial agentcomprising a material or mixture of materials that, when present in acementitious mixture without fly ash or another combustible ash in saidamount causes less than 2 vol. % additional air content in thecementitious mixture, wherein the sacrificial agent comprises an organiccompound, with the proviso that the sacrificial agent does not comprisepolyethylene glycol (PEG) or aromatic compounds having carboxylic acidgroups, or salts thereof.
 2. The method of claim 1, wherein said amountof said sacrificial agent exceeds an amount necessary to neutralize saiddetrimental effects of said components of said fly ash or othercombustible ash.
 3. The method of claim 2, wherein the sacrificial agentamount used does not result in a substantial increase in air entrainmentcompared to providing the sacrificial agent in an amount necessary toneutralize the detrimental effects of components of said fly ash on airentrainment activity.
 4. The method of claim 3, wherein the sacrificialagent causes less than 2vol. % additional air content in thecementitious mixture without fly ash.
 5. The method of claim 1, whereinsaid fly ash or other combustible ash may vary in content of saidcomponents from a minimum content to a maximum content according to asource or batch of said fly ash or other combustible ash, and whereinsaid amount of said at least one sacrificial agent exceeds an amountnecessary to neutralize said detrimental effects of said components ofsaid fly ash when present in said maximum content.
 6. The method ofclaim 1, wherein said sacrificial agent comprises a compound selectedfrom the group consisting of aromatic compounds bearing either sulfonateor amino functional groups or combinations of said groups, glycols andglycol derivates having molecular weights of 2000 Da or less, andmixtures thereof, with the proviso that said glycol derivative is notpolyethylene glycol (PEG).
 7. The method of claim 1, wherein saidsacrificial agent comprises a compound selected from the groupconsisting of benzylamine, sodium 2-naphthalene sulfonate, sodiumdi-isopropyl naphthalene sulfonate, sodium cumene sulfonate, sodiumdi-butyl naphthalene sulfonate, ethylene glycol phenyl ether, ethyleneglycol methyl ether, butoxyethanol, di-ethylene glycol butyl ether,di-propylene glycol methyl ether, 1-phenyl 2-propylene glycol, andmixtures thereof.
 8. The method of claim 1, wherein said sacrificialagent comprises a member of a class of organic chemicals, said classbeing selected from the group consisting of alcohols, diols, polyols,ethers, esters, carboxylic acids, carboxylic acid derivatives, aromaticsulfonates, amines, alcoholamines, amides, ammonium salts, polyglycols,and mixtures thereof, with the provisos that said polyglycols are notpolyethylene glycols, and said carboxylic acids and said carboxylic acidderivatives are not aromatic carboxylic acids or salts thereof
 9. Themethod of claim 8, wherein said sacrificial agent has a value ofLogK_(ow) in the range of −3 to +2.
 10. The method of claim 8, whereinsaid sacrificial agent has a value of LogK_(ow) in the range of −2 to+2.
 11. The method of claim 8, wherein said sacrificial agent has an HLBvalue in the range of 5 to
 20. 12. The method of claim 11, wherein saidsacrificial agent is a mixture of compounds of different HLB values thattogether provide the sacrificial agent with an HLB value in said rangeof 5 to
 20. 13. The method of claim 8, wherein the sacrificial agentcomprises an ether.
 14. The method of claim 13, wherein the ether isfurther defined as a glycol ether.
 15. The method of claim 14, whereinthe glycol ether comprises ethylene glycol methyl ether, ethylene glycolethyl ether, ethylene glycol n-propyl ether, ethylene glycol n-butylether, ethylene glycol iso-butyl ether, ethylene glycol phenyl ether,propylene glycol phenyl ether, di-propylene glycol mono methyl ether,di-ethylene glycol butyl ether, ethylene glycol di-methyl ether,tri-ethylene glycol, tri-propylene glycol, P(EG-ran-propylene-glycol)2500, or mixtures thereof.
 16. The method of claim 15, wherein theglycol ether comprises ethylene glycol phenyl ether.
 17. The method ofclaim 13, wherein the ether is further defined as a polyglycol ether.18. The method of claim 17, wherein the polyglycol ether comprisespolypropylene glycol 425, P(EG-ran-propylene-glycol) 2500, or mixturesthereof.
 19. The method of claim 8, wherein the sacrificial agentcomprises an amine.
 20. The method of claim 1, wherein said sacrificialagent comprises an alcohol selected from the group consisting ofn-propanol, i-propanol, 1-butanol, 2-butanol, tertiary butanol,1-pentanol, 3-pentanol, neopentanol, hexanol, benzyl alcohol,phenylethyl alcohol, and mixtures thereof.
 21. The method of claim 1,wherein said sacrificial agent comprises an ether selected from ethyleneglycol methyl ether, ethylene glycol ethyl ether, ethylene glycoln-propyl ether, ethylene glycol n-butyl ether, ethylene glycol iso-butylether, ethylene glycol phenyl ether, propylene glycol phenyl ether,di-propylene glycol mono methyl ether, di-ethylene glycol butyl ether,ethylene glycol di-methyl ether, tri-ethylene glycol, tri-propyleneglycol, polypropylene glycol 425 and P(EG-ran-propylene-glycol) 2500,p-dimethoxybenzene, and mixtures thereof.
 22. The method of claim 1,wherein said sacrificial agent comprises an ester selected from thegroup consisting of methyloctanoate, methyllaurate, methylpalmitate,methyloleate, ethylene glycol mono-ethyl ether acetate, ethylpropionate,ethylbutyrate, ethylcaproate, POE(20) sorbitan monolaurate, and mixturesthereof.
 23. The method of claim 1, wherein said sacrificial agentcomprises hexanoic acid.
 24. The method of claim 1, wherein saidsacrificial agent comprises an aromatic sulfonate selected from thegroup consisting of 4-ethyl benzene sulfonic acid,2-naphthalenesulfonate Na, p-toluene sulfonic acid, methyl naphthalenesulfonate, and mixtures thereof.
 25. The method of claim 1, wherein saidsacrificial agent comprises an amine selected from the group consistingof triethylamine, n-butyl amine, aniline, benzyl amine, and mixturesthereof.
 26. The method of claim 1, wherein said sacrificial agentcomprises an alcoholamine selected from the group consisting of2-(2-aminoethoxy)ethanol, di -isopropanolamine, tri-isopropanolamine,and mixtures thereof.
 27. The method of claim 1, wherein saidsacrificial agent comprises an amide selected from the group consistingof urea, dimethlyurea, n-butyl urea, and mixtures thereof.
 28. Themethod of claim 1, wherein said sacrificial agent comprises an ammoniumsalt selected from the group consisting of tetrapropyl ammoniumhydroxide, tetrabutyl ammonium chloride, and mixtures thereof.
 29. Themethod of claim 1, wherein said sacrificial agent comprises a polyglycolselected from the group consisting of tri-ethylene glycol, tri-propyleneglycol, polypropylene glycol 425, P(EG-ran-propylene-glycol) 2500, andmixtures thereof.
 30. The method of claim 1, wherein said sacrificialagent comprises a compound selected from the group consisting of2-butanone, methylisobutylketone, butyraldehyde,1-ethyl-2-pyrrolidinone, N-vinyl-2-pyrrolidinone, and mixtures thereof.31. The method of claim 1, wherein the sacrificial agent present is amixture of two or more compounds.
 32. The method of claim 31, whereinthe mixture of two or more compounds together have a hydrophobiclipophilic balance rating in the range of 5 to
 20. 33. The method ofclaim 31, wherein the mixture of two or more compounds together have aLogKow is in the range of −3 to +2.
 34. The method of claim 31, whereinthe mixture of two or more compounds together have a LogKow is in therange of −2 to +2.
 35. The method of claim 1, wherein said sacrificialagent comprises a compound having hydrophobic lipophilic balance ratingin the range of 5 to
 20. 36. The method of claim 1, wherein saidsacrificial agent comprises a compound for which LogK_(ow) is in therange of −3 to +2.
 37. The method of claim 1, wherein said sacrificialagent comprises a compound for which LogK_(ow) is in the range of −2 to+2.
 38. The method of claim 1, wherein said sacrificial agent comprisesa combination of ethylene glycol phenyl ether and sodium di-isopropylnaphthalene sulfonate.
 39. The method of claim 38, wherein the relativeproportion of said ethylene glycol phenyl ether and said sodiumdi-isopropyl naphthalene sulfonate is in the range of relative weightratios between 1:5 and 50:1.
 40. The method of claim 1, wherein saidsacrificial agent is added to said fly ash or other combustible ash byspraying a liquid comprising said sacrificial agent onto said fly ash orother combustible ash.
 41. The method of claim 1, wherein saidsacrificial agent is added to said fly ash or other combustible ash bymixing a spray-dried solid containing said sacrificial agent with saidfly ash or other combustible ash.
 42. The method of claim 1, whereinsaid amount of sacrificial agent is at least 0.01% by weight of said flyash or other combustible ash.
 43. The method of claim 1, wherein saidamount of sacrificial agent is in the range of 0.01 to 2.0% by weight ofsaid fly ash or other combustible ash.
 44. The method of claim 1,wherein said amount of sacrificial agent is in the range of 0.1 to 1.0%by weight of said fly ash or other combustible ash.
 45. The method ofclaim 1, wherein said fly ash or other combustible ash consistsessentially of fly ash.
 46. The method of claim 1, wherein said fly ashor other combustible ash comprises a blend of fly and anothercombustible ash.
 47. The method of claim 1, wherein the sacrificialagent, when present in the same cementitious mixture without fly ash orthe other combustible ash in said amount causes less than 1 vol.%additional air content in the cementitious mixture.
 48. The method ofclaim 1, further comprising the step of selecting a sacrificial agentcomprising a material or mixture of materials to reduce or eliminate theeffect of fly ash or another combustible ash on air entrainment in acementitious mixture and selecting an amount of the sacrificial agentsuch that the amount is at least an amount necessary to neutralize thedetrimental effects of components of said fly ash on air entrainmentactivity and the amount of sacrificial agent causes less than 2 vol. %additional air content in the same cementitious mixture without fly ashor the other combustible ash.
 49. The method of claim 48, wherein saidfly ash or other combustible ash has a predetermined maximum carboncontent and the amount of sacrificial agent exceeds the amount necessaryto neutralize the maximum carbon content in the fly ash or othercombustible ash.
 50. The method of claim 1, wherein said components arecarbon content.
 51. A method of addressing the variance of carboncontent in fly ash used in cementitious compositions to provide acementitious composition with a substantially constant level of airentrainment, comprising: selecting a sacrificial agent and an amount ofthe sacrificial agent such that the amount of the sacrificial agentexceeds the amount necessary to neutralize the maximum carbon content inthe fly ash, mixing the sacrificial agent with fly ash or anothercombustible ash to form a pre-treated ash, wherein the sacrificial agentis combined with the fly ash or the other combustible ash in at least anamount necessary to neutralize the detrimental effects of components ofthe fly ash or the other combustible ash on air entrainment activity inthe air-entraining cementitious mixture, the sacrificial agentcomprising a material or mixture of materials that, when present in acementitious mixture without fly ash or another combustible ash in saidamount causes less than 2 vol. % additional air content in thecementitious mixture, wherein the sacrificial agent comprises an organiccompound, with the proviso that the sacrificial agent does not comprisepolyethylene glycol (PEG) or aromatic compounds having carboxylic acidgroups, or salts thereof.